AviatorAce

Most cars with XM will have an antenna that looks like a black 1/2 inch thick rectangle box with a small stubby antenna poking out. However, this does not guarantee it will have XM. It may just be the style of the radio antenna or it may have XM, but it just isn't activated. The only true way to find a car with XM is to try the radio and make sure you can tune into an XM channel besides the activation channel and the POTUS channel.

You should also look at the model of the car you are getting. Some cars may look nice but will only be a base model, others may have a few dents here and there, but they could be a higher end trim version with heated/power seats, XM radio, more power etc. Also, don't be afraid to try something new, you can fall in love with cars by randomly trying them out. If you are driving a car to the checkout booth and it doesn’t feel right or you can’t seem to see over the hood, just drive it back to the isle and chose something else, there’s nothing wrong with that.

When you're in the aisle, please behave like an adult, don't rush over to a car you see someone walking to and cut them off just because you like the color. Or if you’re by yourself and chose an SUV and then you see a family of 5 trying to squeeze into a Nissan Versa (it’s been the only car on the isle before), offer them your car if you don’t need it; you don’t have to offer it to them by any means, but it’s a nice thing to do and eventually what goes around does come around.

Most importantly, have fun. Every time I go to National I become like a kid in a candy shop and it’s (almost) always such a fun experience. Oh yeah, don’t forget to see what your insurance and credit card cover before you go to pick up your rental, 98% of the time you won’t need any additional insurance.
Hope this helps.