actually, i think your internet connection is part of the game. the same applies to wheels. for example if your wheel brakes during the race, you cannot just say: "oh sorry, my wheel broke while racing, i will rejoin and you count all the laps together, ok? ah and forget about that crash i've made, it was my wheel - not me"
if you have a bad connection, FIX IT. if you cannot provide a stable connection for the race, YOUR PROBLEM. as long as the server is not responsible for any time-outs i do not see any point in leting people rejoin and even add up their laps.
there is also one more thing which makes me a bit suspicious:
e.g. someone is in the way of crashing, he just unplugs his network cable (can be done pretty easy) and times out. afterwards he comes back and says: "sorry i timed out, the crash was because i've timed out but now i am back and will you just add my laps up. ok?"
look at MoE, every timeout they had (and in a 24h race there certainly are a lot of them) will bring a 2 lapspenalty to the team. as the storm cup races are not that long i just stick to my opinion:
if someone is timing out, its his fault and a rejoin will reset his lap count to 0.
btw. i did that: "add laps after rejoin" in the first season of lfscar 360 cup. it was a shit load of work and i had 2-3 times the feeling the one who rejoined just wanted to cover a driver mistake... so i changed the rules from season 2 on: if you time out, you start with 0 again - period.