Although I like our Audi Quattro and consider it good value -it is not a match for the MB wagon 4-Matic I used to own.
Mercedes being much heavier car, with cargo space like double of Audi was using less gasoline than Audi.
Did you check how much timing belt replacement cost on Audi?
Now 14 years old BMW with 235k and CEL on sounds tempting
Well I've done plenty of water pumps & timing belts on E30s bimmers. Was happier when I had my 95 525 and didn't have to worry about belts.
Not familiar with with the V8 bimmers just SB Chevys. But an engine is an engine, not exactly rocket science.
I do like the coil over package for spark plugs, makes it quick and easy.
Parts cost is all I'm worried about because I can fix about anything, with exception to maybe an engine overhaul, but you never know.
Have done gaskets, pumps, brakes, filters, alternators, thermostats, clutches, things of that nature, even OBD I p-chip swaps and dif upgrades from other model car BMWs.
I'm single so I can do with a smaller car. 4 doors do help a little on insurance cost though I do like the added HP of a V8. Audis do suffer on MPG because of their AWD, but my sis 00 E320 4M does really well in that area. So what's Audi's excuse.
If I get the Quattro I'll hold on to it through next winter. If the Audi cab, it will be a fun summer time car then I may hock it after that.
I really like to have different cars to learn from. What some ppl might throw caution signs to I call it typical maintenance.
I do like the 540i 6 spd. Maybe I can talk him down a little in price because of the high mileage and CEL. I already have a good idea of what's causing the fault, but wont know until I drive it.
Whatever the case I'll more than likely have another car by the weekend.