My daughter's just got to the point where she can ride a bike with no help from me so I just very excitedly bought my first bike in years.

I'd love to go further afield on bike rides but just can't work out what roof rack is compatible with my car. There are plenty of sites that offer a filter based on my car model or registration but it's not clear whether I'd need anything else to fit them and also exactly what the specifications are that makes it suitable. I don't have a huge amount of money so I'd rather get something second hand, so knowing exactly what I'm looking for is essential. A filter just won't do.

I've searched through my car's user manual but couldn't find anything.

Does anybody have a link to a website that can tell me exactly what I need or possibly help me work it out?

Thanks!