....the lawyers can decide which!
I've just found out about a problem that some german aquaintances had with car hire at a UK airport recently. They had booked a car in the Golf/Astra/Focus/308/i30 class. When they arrived they were presented with the UKs greatest contribution to the mobile fashion accessory trade - the MINI. This had nowhere near enough luggage space but the company was claiming it was in the same class and therefore valid in their terms, no other car in the class was available. In the end an extra £200 was paid for a bigger car.
The reason why no other car was available is that they wanted an automatic, this is usually the starter class for automatics. Manual gearboxes were available in numbers but only the Mini or bigger with an automatic gearbox. And this means US visitors are most likely to be caught by it.
The reason why I say ripoff/scam is that a Mini, even the 5 door version, is NOT in the same class as the cars quoted! So they should have been given a bigger car at no extra cost. If you have booked a Golf/Astra/308 sized car and the example list did not include Mini, save the link to this warning onto your mobile device. Or print it off together with one or more of the following UK published reviews which list other cars in the same class as the Mini. Then if they try this with you, present this evidence and tell them I will help you take the case to their local Trading Standards Office (which foreign visitors usually don't know about!). As you may have noticed, I am not happy!!
https://www.whatcar.com/mini/5-door/hatchback/review/