I have a 54 reg Santa Fe and had a towbar put on by my local garage,3 1/2 yrs ago , consideraby cheaper than the Hyundai dealership and there were no problems in sourcing it through the internet or fitting it, nor any problems when it was in another Hyundai dealership for repair just before expiry of 5 year warrantyin August 2009( it needed 3 "core plugs" replaced whatever they may be, but I do not think that this is a common problem in this model, I think I was just unlucky ) If you are going to buy a 54 it will be out of Hyundai 5 year warrenty now anyway. I do not tow much, so cannot comment on that ability, but I drive 46 miles a day to and from work and it is very reliable, the core plugs being the only problem in 4 1/2 years with just under 70,000 miles on now .The only other complaint that I could make is that the steering is a little vague, compared to some other cars I have had. They do depreciate from new but you should be able to pick up a 54 at a very reasonable price, and have a sound good tow car with plenty extras re spec.
Hope this helps.
dock32