It looks similar to this and carries up to 3 bikes I think. Halfords 3 Bike Rear Mounted Bike Rack £99.99 new. Seems to be in good order. I got it from someone and then never used it so it's just been stored. Decided to give it away to someone who could use it.
https://www.halfords.com/cycling/bike-racks/rear-mounted-bike-racks/halford...*17je75p*_up*MQ.*_ga*Mjg3NDM5NDc1LjE3MTUzNDE5MDA.*_ga_EG1MQMYCLS*MTcxNTM0MTg5OS4xLjEuMTcxNTM0MTk1MC4wLjAuMA.*_ga_VK44BRER97*MTcxNTM0MTkwMC4xLjEuMTcxNTM0MTk1Mi4wLjAuMA..

Bike rack to go on back of boot lid (Pitchcombe GL6)