We’ll be selling our 1995 Audi A6 1.9TDi at some point in the not too distant future, Depends how tall you are but it’s not quite long enough for me to sleep comfortably at 6’2″. Will do 800 miles on a tank, does about 40mpg with a boat on the roof and a boat behind. You’d probably want a car before we sell ours, but I’d highly recommend one. Ours has done 285k miles, 200k on the current engine. Will fit my Large specialized in the boot without folding the seats down (wheels off obviously). TBH if i was going to get something to sleep in for a week I’d get a van, I think I’d get fed up of the lack of space to move around, but I’m lanky and clumsy so you may well differ.