After the above so I don't have to keep taking it off when the Mrs drives, does this exist?
Vauxhall have something that is factory order but thats it I think.
Yeah, a couple of manufacturers now do pull out racks which are built in to the car but they are normally factory order.
Have you had a look at the Thule 931 easyfold? Not sure exactly what you are after, but the 931 folds up small enough to fill up about half the footprint of my boot (or much less if you stand it upright), and can be fitted in about a minute.
Doubt the Vauxhall style built in racks will be an option unless you are in the market for a new car?
They're also around £500-1k!!
Half that will get you the towbar, fitting and a top end Thule you get to keep if you change cars.
Witter zx5?? Racks can stay on the tow ball as they fold vertical. There's videos on the witter website
roof rack + carriers
Maxxraxx folds up quickly and is small enough to keep in the boot (considering they do a 5 bike version)