I've never seen a keyhole cover, can they be taken off and put back on easily? I was intrigued with the idea at first but rom the sounds of it though, it would make the valet key and wallet key (in the event you lost your main key while out) useless. Is this true, or is there a way to still use them?

I was recently keyed and thought about extra security for my X (not that it would prevent being keyed again, but help theft prevention - noting it nothing is 'steal proof')