Yeah, internet lag really screws things up sometimes since karts start to teleport or experience godly acceleration and speed. I think Nintendo really needs to work on Mario Kart netcode (both for 7 and 8) since these are probably the only Nintendo games that are both competitive and timed. I agree that it can also be a user-end problem, and that can be addressed by other means too. The end goal is to have a seamless online multiplayer experience not just 95% of the time but 100% of every single race.