Hi, there isn't an IS300 any more. The Lexus IS series comes in a 250 or a 350. I drove both, and found the IS350 to be a very good value. The engine is fast and very responsive. From a performance standpoint, though, the big drawback is that it only comes in an automatic. You can get a manual in the IS250. The automatic in the IS350 is pretty good, probably the smartest automatic I've used. It gives you fast launches when you want them and is pretty good about downshifting when needed.
As for aftermarket tuning equipment, I don't think there's much of use you can do to this car.
Hi, im currently in the market for a new car, and have been looking into the Lexus Is 300. i was just wondering how this car is, and if some one has it how do they like driving it? Also i would plan to through in some extra stuff into it(turbo, exhaust, intake...). So is this the type of car where i could do that too? Also is there any noted problems with this car that i should look for when looking at the car? Thanks.