I need a new car, but I first need to get a new rack for my kayaks. My wife has a Toyota Highlander, and I plan to get a Nissan xterra sometime this summer. I want to go with a Thule rack system, but Im not sure what size crossbars would work best. Thule recommends 50 for the xterra, and 58 for the Highlander. Im thinking about 65 for both. I might be able to get two kayaks on a rack with 58 crossbars, but the extra 7 would make it much easier. Are there any problems with using crossbars that are that much wider than the factory racks? I understand that I should not put a lot of weight on the overhanging sides, but are there any other issues? Thanks!