Until recently I would have agreed ,`Not the bulbs' ; however, have just had a freaky intermittent problem with wifes Dodge Spirit; after the usual exhaustive check of wiring and grounding points the problem persisted until I changed what was apparently a perfectly good bulb; then end of problem !I have a 2007 Malibu. I've been having problems with the rear light system. First, my rear right signal light went out, then the left a few days later. The front signals work fine, and the dash signal indicators go twice as fast as they did before the rear signal lights went out.
Now my whole tail light system is being screwy. Sometimes the lights work...sometimes they don't. I noticed just yesterday morning that they were working when I unlocked my car via remote, but that afternoon, they didn't.
My husband checked the fuse box, and everything looks fine, so I'm thinking it's a wiring problem. It wouldn't be a bulb issue, would it?
Try bulb change first as it's easiest; then work through grounding points; then wiring.