Hi Wolfe, thanks for your reply! Yes, in the meantime I found, that I could avoid such "invisible wall" behavior with a positional change (on theY-Axis) of the VehicleBody. Its y-origin is now located below the VehicleWheels y-value which seemed to solve the problem for me.
I know that many people ditch the VehicleBody/Wheel in order to implement their own solution. Either its too complicated to set up for arcade or it lacks the ability for a proper simulation =) Me too tried different arcade approaches (KinematicBody and Ball-model) but I found, that while easy to implement, they bring their own problems on the table when trying to go for a good arcade feel. So I found the Vehicle-nodes a good allrounder and as I said - the values given above in the threat make for a good start (in my opinion).
In addition I am experimenting with curves to change i.e. the max steer angle in relation to the speed or the wheels slip value in relation to the duration of the pressed handbrake. At the end, there are many values to tweak which make it difficult to get it right all together as well - but for now its fun =)
I am aware of your project, its pretty impressive. Together with Trackmaster and Loose Bolts (...and Truck Town :p ) probably the most advanced driving driving/racing projects in Godot.
A bit OT: Do you plan to go multiplayer?