Thanks to a rather frustrating knee injury, I find myself unable to easily get in and out of the car I own, which is a bit too low to the ground. As such, I'm looking at the possibility of renting something taller -- probably a small/standard SUV or a minivan -- for a month or so until I'm in better shape.

While I rent frequently, I've almost never rented for more than about a week at a stretch, so this is uncharted territory for me.

Does anyone have any tips on how to go about getting a decent rate on such a rental from National or Enterprise? I'd rather keep the credits in the family, since I'm behind on requalifying for Exec and this injury is probably going to limit my business travel as well.

I am in the Boston area, if it matters. I'd be fine with swapping out the car on shorter contracts if that ends up costing less, though I'm probably not up for switching locations.