Best thing is to remove as much trimming from your car to see if there is any hive.

Pandan leaves will help too for long periods of time.

Remove any damp carpeting & dry them.

Once you have done all this, please remember to use precaution to avoid the same thing from happening.

Dont eat in your car.
Dont park near rubbish dumps/dirty drains or any place that looks even remotely dirty.

Dont expect this to be done in a day, allocate few weeks. Even then you might see 1 or 2 running about.

Happy hunting