Sorry, but I beg to differ since I had the same problem. I had already replaced the socket which was an expensive little piece of plastic from the dealer that changed nothing. So, I was at the local automotive shop to buy a new bulb "again" and I saw that they were out of stock of the proper bulb which has a plastic base, but I saw one that looked identical that had a glass base and a different number so I thought I may as well give it a try and now several months later that same bulb is functioning fine with no "melting' issues that occurred with the so-called proper bulb. Sorry don't have the bulb number at the moment but you should be able to spot it in the rack of bulbs for sale.
I found the same bulb recently. The base was made as an extension of the glass bulb so that there was no plastic to melt. The model number was the same. I think it was an 3057NA same number but some manufactureres make the base from glass.