I had an absolutely filthy car. I have two dogs that I love bringing on hikes, drives, etc. I haven't cleaned my car in at least a year and it practically had more dog hair in the back seat then on my actual dogs.
I bought the Groupon and called to schedule my appointment. It took a little bit of phone tag, but they came out and cleaned my car. It was pretty spotless and my car looks newer than when I bought it. There was an extra $20 gas fee, but it was worth having a fresh smelling car.