There are many different function of 4 pin automotive connector housing(also called 4 way automotive connector housing). You can see them in automotive instrument, lighting system, fuel pump and so on. Most of those 4 pin car connectors are made from PBT, due to PBT has excellent chemical stability, mechanical strength, electrical insulation and thermal stability. It's also stable at higher temperatures.
PBT has very weak hygroscopic properties and does not absorb water at high temperature. On the contrary, PA66 can maintain strong strength and stiffness at higher temperatures. PA66 is still hygroscopic after molding. That means all the 4 pin automtive connector and housing can be worked in high temperature environment.
All the 4 pin automotive connector and housing Langrun produced are comply with RoHs and REACH requirements.