Alright, I'm breaking the rules. It's on Autotrader, not eBay, and it's $900 over budget, so sue me. But hear me out, because this 1977 W116 450SEL 6.9 is everything a Mercedes should be. Big, safe, fast, high tech, luxurious, understated, cooler than hell, and black. You can't not look awesome . My god this car is…