If it is an original floor and doesn't have any new paint over it then get some acetone it is mean and will not hurt a cured gel coat. if that doesn't take it off it isn't coming off. get it in paint department at home depot.
I like it! Looks like the original floor... I'll test it in a hidden spot first though. Didn't even give acetone a thought... I've used it on other things in the past and you're right... if it doesn't come off with that, its not coming off. Thanks... I'll try tomorrow afternoon. Guess I'll have to pull the rubber matting out first...lol... unless I want a big mushy mess back there...