Almost all operators impose a restriction against their cars being driven in Mexico. Many operators now impose a restriction against driving on unpaved roads . Some operators impose a restriction against driving their cars in parts of New York City, especially the island of Manhattan. All normal rental cars in the USA and Canada take unleaded petrol, which is universally available. Cruise control, central locking and electric windows are common.
Sunroofs are very rare, however.
All normal rental cars have automatic transmission, which is very easy to get used to provided you remember that when in gear the car will creep unless you keep your foot on the brake. Since the rule of the road is to drive on the right, the driver sits on the left. However, the accelerator is still on the right and the foot brake in the middle. Before you return a rented car be sure to sort out all the items which have doubtless collected on the back seat, in the glove box, in the door pockets and in the boot during your trip. You normally have to park the car in a queue and then collect all your luggage and remove it from the car very quickly, so it's well worth getting yourself organised in advance.