Hi, I have done some investigation. The sponsor thing was a bug, now fixed in 1.0.9. The car development thing is simply because your current engine supplier has a high Research stat - they're contributing toward your car's development with new engine parts. About the finishing positions thing - while I have no idea what can be causing it, I have now gone to near-extremes to prevent from happening (cars when crossing the finish line enter Lap 99,999 minus two times the number of cars that already finished - it'd really take some doing to interpret that wrongly).
Build 1.0.9 is now live.