I had a similar situation very recently. I finished a house renovation (not the one I live in) over a period of six years. I had pulled permits for various phases of the reno over that period; some got the final sign-off, some did not. Put the house up for sale, and a potential buyer, as part of their due diligence, tried to get copies of the permits from my town inspection department. The clerk there noticed that a couple of the permits had been open for nearly three years, and contacted my wife. The clerk reminded us that without a final inspection, we could not get a Permit to Occupy the house. We wasted no time in getting the inspector out to the house. He noted a few things he wanted corrected, which we handled promptly, and then he gave us the permit. Cost was $45.
I know that a garage is different, and probably doesn't need a Permit to Occupy (or whatever it's called in your area). But you really owe it to yourself to make sure all the permits are closed, especially if there is a chance you'll want to sell the place someday. And when the inspector shows up, politely say "Yes Sir" to anything he judges necessary, and get it taken care of. You definitely want to stay on his good side. You'll be happier in the long run.
Listen to the people who say "don't bother" at your peril.