How big is the car and what sort of riding are you planning on doing on these bikes?
Along with the usual small wheel compact fold variety you could consider a full size frame type that hinges around the seat tube if it is purely for convenience of lobbing in a car to ride elsewhere. Dunno much about them now, my last one was a long time ago, a 26" wheel MTB, fitted in a Mk1 golf boot with some space to spare.
For more conventional idea folders: check out
Decathlon's different ranges of shape & price points. Mezzo, Dahons & Terns get nice write ups & seem well received by owners on various forums. I assume the product recall that affected Tern's last year has been addressed now, but if you were
ebay'ing for a 2nd hand one then something to consider.
Around and below this level you've got the
Halfords: Apollo, Raleigh, Carrera types typically around the £200-300 mark.
Other than that there's e.g. Land Rover, makers who are maybe not big/serious players in the market but have put out something better than a Chinese Brompton clone.
Bromptons are mid price range folders really, Birdy's start around £1k and go up from there, Moultons, Airnimals etc even more so.