Screws thru the vinyl covering is visible tacky. I was going to position bare rubber, drill hole thru rubber and FG dash then drill countersunk hole size of a small carriage bolt, apply RTV/silicon goop to hold carriage bolt and fill in over the head -- then finally cover with the vinyl and apply trim pieces. The square bit on the head and the RTV should keep bolt from twisting. I like Gordon's wing nut idea too.