I like the landmines idea! They would add important strategic element to the racing if they were limited amount for one race. You could stop backdrafters from gaining advantage from sticking at your ass, which is gay, but with landmines you just press the button and bam! It would also encourage clean racing, since you wouldn't need to make zig-zag patterns on long straights.
Oh yes wreckers, I hear you say. But I think that it would not in any way have negative impact in an act of wrecking, because now wreckers just block the track, with landmines they could just mine the track, giving you the better chance to dodge.
Before you hardcore elite VIP sim maniacs burn me down in flames, please consider how many people would buy LFS if it has landmines and how many dollars could devs earn for their living!
edit: LOL good one, hey there tristan!