I looked at this way, it cost me roughly £500 including the petrol. I simply felt in retrospect that I could have spent that amount of money on something that I would have got more enjoyment or value out of (car related or otherwise). But as you've seen, others feel that it definitely was worth it for them. Unfortunately, unlike a physical item, you can't take it off and recoup some of your money by selling it if you decide it wasn't worth it. On the other hand, it's not going to do any harm.