I use a Saris Bones rack.
Before purchasing I checked the Saris web site for the correct racks for my car, all manufacturers should have this facility.
One check worth making - the upper mounting will likey rest on the window, in my view if the window is fixed to the tailgate from the inside, then perhaps there's a risk of it being pushed-in so I wouldn't use this type of rack (or any type of rack) on such a car!
If the number plate and/or rear lamps are obscure you will need a lighting board, be aware that the electrics to power one might be expensive for your car so check first.
Advantage of boot mounted rack - easier to lift bikes on and off, can fit a cable lock around bikes and onto car's rear towing hook (you might have to screw this in if not permanently fitted). Disadvantages - restricted access to boot, possible need for trailer board, risk of rear-ending damaging bikes, may get muck off rear wheels onto bikes in wet weather, straps get all tangled up in storage! Fit too tightly can bed tailgate/boot lid, too loosely - well, you've seen them haven't you on your travels!
Advantage of roof mounted rack - no need for trailer board, no risk from bike damage due to minor rear-ending, rack stays on car so you don't have to re-attach after a tiring ride, can get into boot Disadvantages - need to lift bikes up, risk of smahing bikes on height restrictors (my friend did this, drove into a layby with a height restrictor on it, bikes, rack and all ripped off roof, lots of danage to car as well.
I originally used a Bones 2, with the single upper leg, but swopped it for a bones 3 with 2 upper legs for better stability. Use "hatch huggers" so as not to clip onto edge of rear window or fragile bits of car.
I've carried bikes with a Hollywood rack, towbar mounted racks (I owned a caravan anyway so no extra expense) and the Bones, never any issues except when I used the 3 legged bones on the MX5, the 4 legged one is better 'cos the legs go either side of the high-level brake light. I've been allover the UK with bikes on the rack, even 4 bikes on the Hollywood rack from Brum to Donegal, touring in France etc. no issues BUT frequent stops to make sure all is secure is a must
Brompton, Condor Heritage, creaky joints and thinning white (formerly grey) hair
""You know you're getting old when it's easier to ride a bike than to get on and off it" - quote from observant jogger !