IS300 fitment is one of those things that sounds scary until you actually look at the numbers — then you realize the only thing standing between you and a clean setup is deciding what matters more to you. Here's the cheat sheet: 1. The front is the whole game. Rear clears almost anything reasonable, but front suspension geometry and the fender lip will humble you fast if you guess wrong. Measure twice, order once. 2. Square setup (same size all four corners) keeps life simple — you can rotate tires, replacement costs stay predictable, and the car stays balanced in the rain. Perfect for the IS300 that still sees winter or daily duty. 3. Staggered setup gets you the look. Wider rear gives you that planted, aggressive stance the IS300 was always begging for. Trade-off is you're married to directional mounting and buying tires in pairs. 4. Offset is where most people fumble. Too aggressive up front and you're kissing fender liner on every bump. Too conservative and the wheel sits so f...