Completely agree with mrodgers here and partly with Neil..
mrodgers point.... Completely correct, if anyone is 20 seconds a lap slower than everyone else, and the leaders are coming up on them, then yes, gtfo of the way please. If it is a different class, then of course the rules change, but again, the chances of you battling for a position is tiny, and the leaders are the leaders. There is such a small chance that the leaders of the XFG class are going to be lapped by the XFR class in a short race that it shouldn't be an issue...
Neils' point... If someone is on the lead lap with you and is 2 seconds a lap slower than your best ever time, tough... It is up to you to pass him, that is called racing
You have 0 rights, and he should do everything in his power to block the racing line. This doesn't mean swerving over the road and making more than two distinct moves, but it is completely what racing is all about.. This is where skill and experience comes in, rather than hotlapping ability. You HAVE to out-think your opponent, not just out speed them