Watched it on Toonami and then bought it when it came out on DVD. I can't say I ever got insanely attached to it, but when it was on TV it was fun waiting for the race each weekend. The humor is really good, and there's some very well designed characters. The races occasionally get monotonous, but it throws in a particularly well-choreographed one every once in a while to keep it interesting. As to the rating, season 1 is pretty much okay for 8+, as the bar says, but season 2 you have to be more carefull with - for some reason they really bumped up the language-content in S2: d**n, h**l, b***h, b*****d, a**, maybe a crap or two, no f-bomb or anything like that, but it's definitely more testy. So for S1 I'd say 8+, give or take a year, for S2 maybe 12+.