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I have a Seasucker Bomber 3 that I used one time to test it out once but never used it on a trip. I bought it for my Model 3 but now I'm trading to a Model Y with hitch so I don't need it anymore. I would be willing to sell it if you're interested.
I use a Seasucker Mini-Bomber. Carried two Tarmac SL7 bikes 1,100km from Edmonton to Vancouver on the roof. Checked the suction every time we stopped to charge. Never had a problem. It was frankly a bit terrifying to have them up there held on by a piece of wood and suction cups...but it worked.
You'll likely read that the suction cups have caused cracks in roof glass. I'd say use discretion...don't go carrying two or three 20kg mountain bikes on your roof. Make sure the rear wheels of the bikes are on your trunk lid. Mount the bikes as far back as you possibly can.
Hope this helps.
(Photo is not mine, but that is how I mounted the bikes...)