Renting a car at Edinburgh Airport is easy; there's a free shuttle bus from the bus stop, taking about two minutes. During the rental process, the rental agency kept trying to upgrade, mentioning mileage limits, GRPs, and insurance fees. Luckily, I've been renting cars in Europe for a long time and didn't have a language barrier, so the rental process went relatively smoothly. The only annoying part was the constant haggling; I ended up paying extra to upgrade to a Q5. The car was in good condition, a brand new model.