Agree with the tight traffic in Amman but I rented a small Kia Picanto, pretty similar to the size of car I drive in the UK. Hardest thing was learning to drive with a gear stick on the other side, and a clutch that is so low (mine is on its way out)

I was advised to only drive in and out of Amman by other travelers but found it no where near as headache as they made it out to be. Even got caught in rush hour on my back, just reminded me of UK stop start traffic.

Also the full coverage for my car was pretty reasonable so got it, though didn't need it.