This. I did the exact same thing. Grabbed one out of the dash and went to the local hardware store. The annoying part is it's one of those thread sizes that you can actually use either standard or metric. You can thread it long enough before any locking happens because the threads are so close. One might be just a little more snug though.Unscrew one and go to the local hardware store to find out what screw thread/size it is. They should have thread/size guage. You can try on nuts from the bulk bins also to check sizes/pitch. Once you have that, you can go online if the local store doesn't have what you're looking for. Also check the local auto parts stores.