I have a mild gripe with both the "deal" and the carwash. For reference, I have a blue Honda Civic and a champagne Ford Ranger with a camper shell. Both have been through 1-2 times per week for the past 4-6 weeks.
Deal: the "Fine Print" fails to mention that you can only enroll one car. This is an understandable limitation but one that wasn't disclosed until after I redeemed the voucher. Classic bait and switch.
Carwash: I believe the carwash is fairly new and they appear to be making tweaks to improvement.
It does a great job cleaning your car. It does a lousy job drying your car. The first few weeks it wasn't so bad, only the left side was a little wet. The most recent modification made this a little worse, for the past few weeks I have had to park and dry my vehicle to avoid milky white water spots--not just in one area but the whole vehicle.
As of right now, I would not recommend this carwash unless you are okay with water spots or okay with spending several minutes drying afterward. I will cancel my auto-renew subscription if the drying issue isn't resolved.
In summary, the $11/lava option cleans both of my vehicles very well. I keep a towel in both vehicles and take 5 minutes to dry afterward and it works out well.