There are several problems or bugs that prevent vehicles used in Mainland:
1 - If i try to enter with one vehicle in a full plot or if my car has more prims that available in the plot, my vehicle is returned to inventory and lossing the control of the avatar. The message that i receive is:
Second Life: Your object 'Helicoptero v0.2.0' has been returned to your inventory lost and found folder by xxxxx xxxxx from parcel 'xxxxxxxxxxx' at XXXX 47, 254 because the parcel is full.
Additionally, if I recover the control of the avatar, that he got stuck and unable to move with the animation of the vehicle.
2 - If i crash again one banline, the symptoms are very similar to the previous case, especially if the plot is in another region.
On some occasions i not lose the vehicle but the position of the avatar in the chair is changed at distances up to 1000 meters and usually underground. And without the possibility of being able to move without rebooting.