I can tell you what doesn't stick: duct tape, electrical tape, cellophane tape, and masking tape. Is there any tape that does stick well?
What are you trying to do with the tape? If you are trying to repair a tear on the seat, try flex tape. That stuff is very sticky and will not come off.
Another tape that is sticky but will show like a soar thumb is Tuck tape. Depends on the intended use I guess.
I have a relatively small plastic case that I'd like to suspend at the bottom of the seat back, rather than have it sitting on the floor. Not heavy by any means.
Depending on the size of the plastic case I don't know if it's clear or what save the cases like the size of a pack of cigarettes take a dab of goop on the back of the cigarette case size plastic box about the size of a quarter and then press that against the seat and hold that or tape it for 10 minutes and then after that remove the tape carefully and let it skin for about 8 hours before you put stuff in the plastic box or whatever is going on with it if it's the speaker or something don't turn it on for about 8 hours let everything cure then when you need to rip it off you can just take a plastic splooge behind the plastic box push a little bit and pull on the box and it'll release and leave the glue on the seat which you just roll up with your fingers and throw away.
I was about to propose Amazing Goop, but not sure if it will react to the vinyl. Maybe try in a non visible spot first? That stuff is amazing.
The real leather may actually react with the goop and lighten the leather so the gray will become a lighter gray almost White look like a bleach spot. This is possible so you may want to try it on a piece that's folded over first that won't be affected or do it on a cut a piece off of a junkyard back seat seat back the front seat but just cut a little piece off put some goop on it squeeze two pieces together let it sit a day or two a couple of days then pull it apart and roll it up and see what you have if you can't live with that well then you got to do something else I guess a lot of these glues that aren't available today or that are harder to find like barge cement and things like that are made to glue leather shoes and things like that so it is possible when they're glued and then ripped apart or unglued that the glue does some damage or staining to the leather because these glues are very strong and they were made with chemicals today that well people don't like but they worked very well that's why your shoes and your soles of your fancy hiking boots or delaminating while you're wearing them out in the snow because these new processes to attach shoes and shoe bottoms to shoot lasts as well not so good. And now all of your shoe brands that you've come to know and love are falling by the wayside because of these processes because of the new ways of doing things until they get it right you pay in discomfort and the shoes falling apart while you're climbing Mount Everest.
