E for me, mine has full air suspension makes it the best tow car I have ever had A6 and 5 would be in the same boat, good large cars with a long wheelbase to overhang ratio Most full size 4wd are to dynamically compromised, ok if all you do is tow There is a guy here who races an historic mini and tows with an 8 series BM, that is one from left field!
Left of field? My first mk1 golf was an X plate forest rally car that I bought on knobblies from Cleveland area. It won some very local championship. Anyway it had no servo and 239mm brakes, so I decided to fit a towbar to it and tow my rallycross mini to knockhill (golf still on knobblies!) to compete. Anyway, it had a fuel leak so was doing about 10mpg, and it was hellish difficult to get six people in it (due to cage..) so we could go get some more tinnies from the offy, as we needed to be comatose due to sleeping outside at the circuit in winter. Oh, the joys of yoof Jon And...........it was my daily at the time. Came 3rd in the superfinal at knockhill in the golf the next visit up there.....it was a monsoon. 1991 or 2 or 3 or somewhere near