Fatz, I'm not doing this to get into an argument, just so the facts are there for anyone considering a good tow car.
Not only bonus for reversing?, I was more thinking of driving forwards through say, a wet grassed parking area. Have been stuck with Q7, never with Touareg, even in mud.
Depends what year, but yes, generally VW 3.0TDI is cheaper.
Never found VW lacking in boot space, compared to Q7, remember Q7 is longer but roofline tapers down, VW is upright, more rectangular.
Just sayin'.