I had exactly that problem with my 'phone charger adapter - the cigarette lighter socket was useless, the plug from the 'phone lead wobbled loose all the time. I tried other leads and USB adapters but they were all the same, I concluded that the socket just wasn't suitable for anything other than the cigarette lighter itself. My solution was to get a 12V to 5V micro USB adapter (mini USB available as well) off of eBay. Wired it into the feed wires that lead to the cigarette lighter (pull up the console to get to the relatively simple wiring underneath) which means I'm on a fused circuit (the cigarette lighter fuse) - current is low anyway. Then feed the output wire (the one with micro-usb) into the ashtray from where I can uncoil it if I'm on a longer journey and want to charge my 'phone on-the-go. Shouldn't use the real cigarette lighter and can't use the ashtray but I don't smoke and I'm never ever going to let anyone else smoke in my car so I don't care about those particular disadvantages.