Unless this 'feature' I'm talking about has been fixed since S1, this might have something to do with the fact that if you join the server midrace, you can only see the drivers' current lap time, and no best laptine even if they had driven full laps already. Then when the race finishes you see the finish time on the results and it's correct but the best laps are only chosen among those laps that your client has witnessed after you joined the game, and not the real times.

You can still see times in this case, maybe it gets totally messed up only by driver change.

Found this while fooling around doing donuts in the pits.

You change tyres and repair your car in 0 seconds in the fashion shown in my demonstration replay. No refuel is done though. I had starting fuel at 50%, 60% at refuel but no addition can be seen in the replay.

Not all pitlanes are suitable for this action though, there are no walls close enough in tracks other than Aston (both pitlanes) and South City. Blackwood looks like it'd work but I wasn't skillful enough.