Results:
When flying across the land, you constantly fly into banlines. This would not be all that bad if I just bounced off of them, but the vehicles stop working, until you get out and then get back in again. But only if the scripter has set STATUS_PHYSICS to true on sit. If the scripter hasn't, then your only hope is to have modify rights, which not all vehicles allow.

When flying into a parcel that is full (of prims) the vehicle dissapears (sometimes not being returned to inventory) and my avatar starts to fly into the void at an ever increasing speed. Attachments start flickering, the stand up button fails to work. The only fix is to try and teleport multiple times until it stops or log out and log back in again. Hardly user friendly.

When flying into a parcel with a security bot that someone has set to 0 or 1 second, you are teleported home, less your vehicle. You then have the fun of teleporting back and trying to find your vehicle.

Improvements:

• Vehicles bounce off of the ban lines instead of disabling physics.
• A) Vehicles bounce off of full parcels.
  B)Are displaced into the nearest parcel that has room.
  C) Or have vehicles not count towards parcel prim usage.
• Banlines as solid blocks that you can see easily from across the sim before you ram straight into them. The colour, opacity, and view distance could be player customiseable. It may actually be fun weaving inbetween white blocks.
• Avatars are invisible to scripts for several seconds to prevent instant ejection when flying over a securty bot without realising it. If they don't want people on their land, then they should use banlines.
• Have all Linden roads allow object creation so we can rez our vehicles. Have a return time of 1 or 2 minutes to prevent littering.

Vehicles could be so much fun, but not the way things are at the moment it.