I love my SL65. I've had two. You don't really need to mess with them, they're plenty fast enuf... and a big heavy mega fast boat no matter what you do to it. I actually do think I'm going to Renntech flash my current one, a '07 diamond silver metallic with red berry premium leather pkg interior with about 30k mi.s on it. Sticker was $205k I paid $58k with 25k mi.s several years ago. Mint car. Flash is good for abt extra 50 hp and 100 tq lb ft, putting it at 670 hp and 840 lb ft. And as earth shattering as it might seem to this crowd.... the trans is no problem!! Rated to over 1000 lb ft. But it could use an extra high gear IMO. Only maintenance issues are / can be shocks (pneumatic or hydraulic depending on model... and expensive Mercedes only proprietary part... but can be coil over eliminated but I personally would not) and on convertibles like mine the hydraulic cylinders, there are 9 or 11 I forget, but if change with rebuilt upgraded ones with viton seals etc they will last for decades. That v12 motor is tried and true and stress tested and proven. I actually think the non AMG 600 cars are rarer than the AMG v12s, but that's just me off the top of my head what I see. A mint looking triple black SL65 with 12k miles just sold on bring a trailer for $48.5k. For performance and power and a decked out uber luxury car, you will not beat that, I don't think. If I stumbled upon the right S65 or CL65 I'd buy it no doubt.