Lag has never been an issue for me. Pings of 320ms - 360ms are acceptable, above that it can get difficult to race close. Good quality European servers are in that range.
Anyway, lag and high ping are two different problems. Lag is more like a bad connection where you don't send and/or receive regular updates, regardless of ping time. Sure, going across the world there is more scope for bad connections but usually its just fine.
Wheel to wheel racing is maybe a bit more risky, but only a bit. I've had hundreds of races on European servers, often very close racing, and its not been a problem at all.
When I have been told that I lag it was because I actually lagged (either not receiving or sending regular updates, usually both), not because I had pings of 330ms.