Skip the holiday special models, get the 14 gallon Ridgid from HD, it is the quietest $100 shop vacuum I've ever heard. Get the WD1451 kit though, it comes with the car detailing kit and extra hose at the same price as the WD1450...
A 1/2" gun might be a little better at it, but it would start running at the end of a lug nut with my MG325. I sold the impact and just use a breaker bar now.
For your uses it will be perfect, but the last time I tried an impact with it it left me wanting a larger tank to run for more than one nut without a short break (10 seconds or so) for it to recharge.