Great little game! I love seeing simpler d100 games. Still, I think adding a heading to each list of skill to clarify the 1st one is ancient/medieval, the 2nd one is contemporary and the 3rd one is futuristic/sci-fi would make it clearer. Other than that, it looks like a lot of fun in 2 simple pages.
Great! By the way, I think the vehicle combat rules have a lot of potential uses besides vehicle combat and chases. They could be used easily to abstract any kind of conflict (e.g. lockpicking, diplomatic bargaining, poetry contests, etc.) if the players or the GM would like to use this approach instead of solving them with a single roll. They also might add tension to a fight scene (e.g. the wizard in the party must complete the ritual to stop the evil demon from manfiesting in our world while the other players keep the cultists at bay; if the wizard fails the three attempts, we are all doomed, no matter how well the other players do!). And now I that think about it, the antagonist's special ability lists can be useful as a template for new special abilities for the PCs.