My dad says that if i had an accident my insurer has to give me a courtesy car of an equivalent size to my car. Is that correct? (My policy does entitle me to a courtesy car!)

Most policies give you no controll over what sort of car the insurer needs to provide. There are a few policies which do give you the option for a like for like courtesy car but they charge you extra for that option.

Check out your policy and if there is no mention of a like for like courtesy car, then you'll have to take what you are offered!

Broker Boy