I just thought I should mention here that we're making some real, if slow progress with vehicle physics improvements. After a lot of experimentation, testing and coordination with the PhysX team at NVidia, we've been making some significant forward moves with the vehicle collision responses.
It's now impossible to fall out of the world, extremely unlikely that you'll ever get jammed inside the scenery and the annoying kick-outs that you often received when riding hard against a curving wall or tunnel have all-but been eliminated.
Next we'll be tackling a custom collision response handler to give the vehicles a greater sense of weight during collisions and stop them getting unintentionally airborne quite so often. Then finally, we'll head into the vehicle setup again to more specifically configure the engine, tyre and suspension code / properties to really tighten up the experience and make GRIP a real joy to play.
These last two stages are likely to take far less time than the work we've done just recently on collision response, so expect some real improvement in the next build, with more to come in the build following that.
Over and out.