I got a Groupon deal with 2 months of unlimited car washes for $15. Included in the membership (normally $5) is their "red towel" service. They give you a microfiber towel to use and when you bring the dirty one back next time they give you a clean one. They include air and vacuums so you can finish up after the tunnel. There are also self-service bays if you want to do it yourself.
I asked about adding one-off services (like wax) in the future and not only did they say sure, but gave me a free wax then and there. I've only been a few times but I'm very satisfied. I wish I could pause the tunnel to give my wheels some extra attention but that's not realistic. I also wish they opened a little earlier but 8-6 is perfectly reasonable.
After my Groupon is up, I'll be continuing my membership. At $16 a month I only need to go once a week to get my money's worth.