The E46 M3 is the last M car you can wrench on in your garage and still end up with something that embarrasses modern sports cars. But here's the thing most people get wrong — they throw power mods at a chassis that's already begging for subframe reinforcement and cooling upgrades. The S54 is one of BMW's greatest inline-sixes ever built, but it'll punish you if you skip the maintenance-first approach. We broke down the full build path so you're not learning expensive lessons the hard way: → Why addressing VANOS, cooling, and the notorious rear subframe comes before anything fun → How to get real gains from the S54 without tearing into internals → A suspension setup that won't destroy your fillings on the daily commute → Wheel and tire specs that actually clear the factory fenders and big brakes → What the total investment looks like and why the E46 M3 is still worth every cent in 2024 These cars are only going up in value. Build it right now or pay double later. Save this for whe...