---
title: "Vapor Smoothing for Automotive Parts | AMT PostPro"
description: "Sealed, smooth 3D printed automotive parts: GM spoiler seals in TPU, ABConcept rally parts in PA12, Langen Motorcycles and Protolabs case studies."
canonical: https://amtechnologies.com/industries/automotive/
updated: 2026-10-09
type: application
---
![3D-printed lattice seat with red lattice inserts on a dark background](https://amtechnologies.com/img/industries/hero-automotive-d-640.webp)

Applications · Automotive & motorsport

# Printed parts, sealed for the road and the rally stage.

Vapor smoothing seals 3D printed polymer parts against fuel, oil and water and gives them a smooth, even finish.[1] General Motors, ABConcept, Langen Motorcycles and Protolabs use PostPro vapor smoothing on parts printed on HP Multi Jet Fusion, from production seals to rally components.[1,2,3]

[Test your parts, free](https://amtechnologies.com/test-your-parts/) See the case studies

Key applications

## Where automotive parts are vapor smoothed.

- ### [Aerodynamic parts](https://amtechnologies.com/resources/case-studies/basf-ultrasint-tpu01/)

  Spoiler closeout seals GM added to full-size SUVs to improve aerodynamics, printed in TPU and vapor smoothed for production.[4]
- ### [Rally car parts](https://amtechnologies.com/resources/case-studies/3d-printed-rally-car-parts/)

  PA12 parts sealed against wear, oil and debris; smooth surfaces reduce drag.[2,5]
- ### [Motorcycle parts](https://amtechnologies.com/resources/case-studies/3d-printed-motorcycle-parts-vapor-smoothed/)

  Fuel tank cover parts and retainers with a sealed, durable finish for the road.[1]
- ### [Flame-retardant parts](https://amtechnologies.com/resources/case-studies/flame-retardant-3d-printed-parts/)

  Flame-retardant PA 12 parts for automotive use, with lower surface porosity.[3]
- ### Interior trim

  SLS armrests with a printed leather texture, before and after vapor smoothing.
- ### [Functional parts](https://amtechnologies.com/resources/whitepapers/enhancing-the-surface-quality-of-sls-3d-printed-parts-with-vapor-smoothing/)

  Air intake manifolds and prototypes with an injection-molded finish, made without tooling.[6]

Printers and materials

## The printers and materials behind these parts.

### Print processes

[MJF](https://amtechnologies.com/learn/mjf-vapor-smoothing/) and [SLS](https://amtechnologies.com/learn/sls-vapor-smoothing/)

The published automotive stories print on HP Multi Jet Fusion. PostPro smooths parts from MJF, SLS, SAF, HSS and FDM[7,8].

### Materials

- [TPU Thermoplastic polyurethane](https://amtechnologies.com/materials/tpu/)
- [PA12 Polyamide 12](https://amtechnologies.com/materials/pa12/)
- [PA11 Polyamide 11](https://amtechnologies.com/materials/pa11/)

[Which system? Compare all four](https://amtechnologies.com/products/vapor-smoothing/)

Case studies

## Two stories from automotive & motorsport.

Each case study is the customer’s published account: the summary here, the full story and the PDF one click away.

1. Case study 01 / 02

   Protolabs production floor

   ### [Flame-retardant parts with UL94 V-0 compliance](https://amtechnologies.com/resources/case-studies/flame-retardant-3d-printed-parts/)

   Protolabs combined HP Multi Jet Fusion in HP 3D HR PA 12 FR with PostPro vapor smoothing for automotive parts that need flame retardance and a molded-quality surface.

   - **Customer**: Protolabs
   - **Process**: HP MJF, HP 3D HR PA 12 FR → vapor smoothed
   - **Result**: Flame-retardant parts with improved surface quality and UL94 V-0 compliance
   - **Published**: Jun 2026[3]

   [Read the case study: Flame-retardant parts with UL94 V-0 compliance](https://amtechnologies.com/resources/case-studies/flame-retardant-3d-printed-parts/) [PDF: Flame-retardant parts with UL94 V-0 compliance (opens in a new tab)](https://amtechnologies.com/resources/case-studies/flame-retardant-3d-printed-parts/)
2. Case study 02 / 02

   Rally car on a desert stage

   ### [Rally car parts built for the desert](https://amtechnologies.com/resources/case-studies/3d-printed-rally-car-parts/)

   ABConcept fitted the Zephyr rally car with HP MJF PA12 parts and vapor smoothed them to seal the surfaces against wear, oil and debris.

   - **Customer**: ABConcept
   - **Process**: HP MJF PA12 → vapor smoothed
   - **Result**: 100+ parts through 2,450+ km of the Rallye du Maroc
   - **Published**: Dec 2025[2]

   [Read the case study: Rally car parts built for the desert](https://amtechnologies.com/resources/case-studies/3d-printed-rally-car-parts/) [PDF: Rally car parts built for the desert (opens in a new tab)](https://amtechnologies.com/resources/case-studies/3d-printed-rally-car-parts/)

[All four automotive case studies in the case-study library](https://amtechnologies.com/resources/case-studies/?industry=automotive)

Automotive on video

## See it at work

[Watch on YouTube:](https://www.youtube.com/watch?v=YCtoCJFK7fk)

### _How General Motors Scaled 3D Printing with Vapor Smoothing | AMT PostPro Case Study_

[Watch on YouTube (opens in a new tab)](https://www.youtube.com/watch?v=YCtoCJFK7fk)

Next step

## See the price. Run the numbers. Hold the part.

Starting prices are public and the cost-per-part math is yours to check, with no email needed for either. The free benchmark puts your own parts, vapor smoothed, in your hands.

1. 01 Quote

   ### Build your quote

   Pick a system and its options, and send AMT an itemized quotation request. Each system shows its starting price.

   [Build your quote](https://amtechnologies.com/quote/)
2. 02 ROI

   ### Calculate your ROI

   Compare your cost per part with manual finishing, using your own labor rate and volumes. Every assumption is editable.

   [Calculate ROI](https://amtechnologies.com/roi/)
3. 03 Benchmark

   ### Test your parts, free

   Ship us your parts with a prepaid label. We vapor smooth them and send them back with before-and-after photos and a benchmark report.

   [Test your parts, free](https://amtechnologies.com/test-your-parts/)

   No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks[9]

Prices: starting prices, excluding tax and shipping; everything else is priced in your quotation.

[Not sure which system? Help me choose](https://amtechnologies.com/configurator/)

Questions

## Questions, answered.

### Can vapor-smoothed parts handle fuel and oil?

Langen Motorcycles reports smooth, sealed surfaces resistant to fuel, oil and water on its vapor-smoothed parts, and ABConcept improved resistance to wear, oil and debris on its rally car parts.[1,2]

### Is vapor smoothing used in automotive production?

Yes. GM’s spoiler closeout seals were a production program: 60,000 parts, needed quickly to avoid delaying 30,000 vehicles, printed in TPU on HP Multi Jet Fusion and vapor smoothed.[4]

### Does vapor smoothing work on flame-retardant materials?

Protolabs vapor smoothed HP 3D HR PA 12 FR parts printed on HP MJF. Vapor smoothing reduced surface porosity on parts with UL94 V-0 compliance.[3]

### Which materials are used for vapor-smoothed automotive parts?

The published automotive case studies use TPU (BASF Ultrasint TPU01 for GM’s seals), PA12 (ABConcept) and flame-retardant PA 12 (Protolabs), all printed on HP Multi Jet Fusion.[2,3,4]

### Can I test my own parts before I buy?

Yes. Send a few of your printed parts to AMT’s benchmarking program and they come back vapor smoothed: no cost to evaluate, parts returned, typical turnaround 2–3 weeks.[9]

## Sources

1. [3D-printed motorcycle parts made to last with vapor smoothing (Langen Motorcycles case study)](https://amtechnologies.com/resources/case-studies/3d-printed-motorcycle-parts-vapor-smoothed/) · AMT · Sep 18, 2025
2. [How vapor smoothing helps 3D-printed rally car parts perform in extreme racing conditions (ABConcept case study)](https://amtechnologies.com/resources/case-studies/3d-printed-rally-car-parts/) · AMT · Dec 10, 2025
3. [Flame-retardant 3D-printed parts with UL94 V-0 compliance (Protolabs case study)](https://amtechnologies.com/resources/case-studies/flame-retardant-3d-printed-parts/) · AMT · Jun 3, 2026
4. [GM's success: vapor smoothing for automotive production (spoiler closeout seal case study)](https://amtechnologies.com/resources/case-studies/basf-ultrasint-tpu01/) · AMT · Jan 23, 2023 · also [AMT](https://amtechnologies.com/industries/automotive/) · also [Forward AM](https://forward-am.com/gain-knowledge/blog/additive-manufacturing-gets-cars-into-showrooms/)
5. [AMT PostPro brochure: automated post-processing systems for additive manufacturing, V4.0 (June 2026)](https://info.amtechnologies.com/download-document?document_name=brochure) · AMT · Jun 2026
6. [Formlabs and AMT: surface quality improvement of SLS parts using vapor smoothing (whitepaper)](https://amtechnologies.com/resources/whitepapers/enhancing-the-surface-quality-of-sls-3d-printed-parts-with-vapor-smoothing/) · AMT · Oct 6, 2023
7. [Vapor smoothing: SF and X-series family page and SFX, SF2X, SF50, SF100 product pages](https://amtechnologies.com/products/vapor-smoothing/) · AMT · read Oct 6, 2026 · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sfx-desktop-vapor-smoothing-system/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf2x/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf50/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf100/)
8. [Vapor smoothing consumables: PostPro Pure (FA5802), FA326 and FA9202](https://amtechnologies.com/products/vapor-smoothing/consumables/) · AMT · read Oct 6, 2026
9. [PostPro benchmarking: send us your 3D printed parts](https://benchmarking.amtechnologies.com/) · AMT · read Oct 6, 2026