So, did you did it for $4,000? Did he take $4,000? That's a good deal, it sounds like to me, if he did! I wouldn't worry at all, it's a good price, real good.
You even are set up with a good mechanic who you can trust and knows the car well, and could help you take care of it! Sounds just great to me!!!
This was a really good car when new, over $50,000, I think, You will really enjoy this car, and be safe and comfortable, and a bit stylish in it.
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1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...
1995 E 420, 170k "The Red Plum" (sold)
2015 BMW 535i xdrive awd
Stage 1 DINAN, 6k, <----364 hp
1967 Mercury Cougar, 49k
2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive
(sold)