I would just like to add the reason for this. Yes, in real life most cars are unlimited on the Autobahn. In other countries are different speed limits for cars and trucks.
In TruckersMP we do not differ between truck and car speed limit at the moment. This has multiple reasons:
Cars have the same (or worse) physics as trucks. We can't change much on the steering behavior and physics because this is a truck simulator.
We are currently mainly focusing on improving the simulation experience for truck drivers because TruckersMP is a truck simulator.
From the technical point of view, we would need to code a dynamic speed limit for different vehicle types that does not exist at the moment.
We might look into this in the future, but for now we will stick with the same speed limit for all vehicles.
Thanks for your understanding.