I have a 2012 RTL which I needed to remove the left front fender to do some work on the wiring under the fender. Since removing and bolting back on the bolts will loosen slightly after a couple thousand miles. When I put fender back on I used blue locktite and probably torqued down more than they were from factory. I can tell when the bolts have loosen because fender will vibrate slightly. Question is how can I keep these bolts from loosening? They don't have any type of lock washer on then from factory, was thinking about putting in either standard split lock washer or washer with the star pattern on the inside. Any suggestions?