For most facilities it is best to consult a waste handler that specializes in this business. Yes, the wash area must be covered and bermed, so that rainwater cannot get into the sanitary sewer, and it must have a device for removing sand and oil. Not specifically, but used antifreeze typically has concentrations of metals such as copper, zinc, and lead that are far above the discharge limit. Used antifreeze should be collected and recycled. Also a good checklist can be found at this website to assist in reducing pollution for those involved in the radiator repair industry.
Solvents associated with paint can generate volatile organic compounds.
All thinners and solvents must be excluded from discharge to the sanitary sewer system. City of Tallahassee, Florida.