I've used these guys for years and have never had a negative experience. They get you in and out quickly and the cost is only $15 dollars with a coupon or Yelp check-in. One note on Smog Hut, they don't have a free redo policy on vehicles that don't pass. Some places will redo a test for free but they usually charge quite a bit more. If you think you might not pass, be prepared to pay twice.