I figured that a game that NEEDS a wireless connection for you to reach 100% isn't right, and they don't need to be done. It's onyl 3%, and there's like 50 races. I can't do them anyway, it says the lobby is unavailible.
Well, there is no character customization. The cars come with paint and sometimes wheel choices, and the only modifications are 3 performance packages, pack 3 being best and most expensive, but still pretty damn cheap. Also, there are houses. You buy them, basically just so you can store more cars. You can teleport to events and buildings you've been to once before so you don't have to drive EVERYWHERE, you only have to do it once. You can teleport anywhere on the island at about 70%
As for achievements, all there are races of course, ranging from different car classes and all that, and there are clubs. Clubs are just random specification things (eg. German Car Club) with 8 races to do so you can reach president, the top level. Once you do you get a free upgrade on your car, and sometimes a free car.