You have surface-00 applied to all objects. If you look into your surfaces.txt
Quote:[surface-00]
Type = none
BumpWaveLength = 0.0
BumpAmplitude = 0.0
FrictionNonTread = 0.0
FrictionTread = 0.0
RollResistanceCoefficient = 0.0
RollingDrag = 0.0
This surface has no friction. The car is sliding, there is wheelspin on acceleration.
You can use the blender importer/exporter to change the surface. Add a new surface-01 group, assign objects to it and remove them from surfaces-00. You also can do it manually. The surface is the last number of each entry/object in the list.txt.