I would use the safest techniques and then work your way to the more agressive methods slowly, as we're dealing with leather. it doesnt help that TSX seats are perforated, so stuff like goo gone can really seep in lol. And whatever you do, DONT scrape! lol.
*remove as much as you can by hand, by pinching and pulling it off, when you get to the base thats stuck to the leather:
*Lexol cleaner, hit it up with a applicator pad, scrub it with minimal to medium effort, let the suds soak it up.
*Use a damp microfiber cloth for the rinse portion, scrub that portion down.
With this method I was able to remove pretty much a tattoo mark from the leather lol (heat from sun +plastic cover with imprint logo left on seat glued it onto it).