It's clearly not a detail. I'd guess the quality will be a little better than a $5-10 wash from a machine- a little more expensive because of the "we come to your car", and also because they cannot bring along the machinery and water recyclers that allow $3 washes.
If they are willing to break out the mitts and buckets of soapy water though, you could have a real nice wash there. Wash != detail, but leaps and bounds ahead of a machine. This is not outside the realm of possibility; I remember my local hand wash place back in the Valley was about $20.
If they are willing to break out the mitts and buckets of soapy water though, you could have a real nice wash there. Wash != detail, but leaps and bounds ahead of a machine. This is not outside the realm of possibility; I remember my local hand wash place back in the Valley was about $20.