A Wash Certificate from Classic Auto Wash is a great way to share – and save! Prepay online for 5 Wash Certificates and get your sixth certificate absolutely free. Each certificate in your six pack is good for one wash, so you can share them with friends, family members, co-workers and employees. Giving a single wash certificate is a great way to say “thanks,” “sorry” or anything else. Plus wash certificates are convenient, just scan them at our self-pay station an you’re on your way to the best wash Downriver, no need to worry about carrying cash or pulling out your credit card.