Roof air cannot be installed as we did not get the roof prep, however others have installed closet air units - usually small window sized units. We have found it isn't necessary for air with the two roof vents, all the
windows and door and we have been in very hot and humid conditions.
I have no idea what your specs are for towing with your vehicle but our TDI Jetta has a tow limit of 1000 pounds. It's certainly capable of more but that's the VW limit for almost all their cars.
No dings on the outside. If you'd like I'll look for more pictures and send in the next day or so - we are actually just headed out camping now