GPL had (has) a lot of editable parameters for the ai with each driver having his own characteristics, agression, skill, etc. in a number of different situations. Added to this the cars were all different abilities, handling and reliability which all together led to some far more entertaining ai battles.
It seems with LFS that each one is identical but a little bit (1 or 2%) slower than the one in front, so if they don't make silly errors they just string themselves out in a long line and there are no real battles.
that is unless you mix up the cqar marquest a bit, but then there are seldom close enough marquest to give a good battle.
I'd like to see each ai have its own parameters, 'personality' and attributes so the faster ones had to balance out greater risk and tyre wear as well as mechanical erosion.