Any ideas on how to clean (vacuum) black carpet in a VW Golf? I had a potential client inquire this weekend. He tried his shop vac(not sure of hp but more than mine). I gave it a try with my shop vac 2hp and no luck for deep embedded sand and grass. Tried turbo brush, crevice tool (ok results, took too long), and regular flat attachment. Then I tried the tape. I didn't use air. What would be next for efficient cleanup? Need some ideas so I can accept job and give excellent results. Thanks in advance.