I should ask , is this for your personal vehicles or for others u may detail ? I use ultima only on my personal and family vehicles it's a little pricey for some of there products but very good . if u will be doing other vehicles u would want something more cost effective . as the other guys mentioned optimum power clean is safe for leather and all interior cleaning and can be used exterior as well , dirty jobs - tires , wheels, engines , lsp stripping . I use opc also and can be diluted to your strength for your purpose , so a gallon will go a long way . carpro perl is great also , can be diluted for interior and exterior applications . lots of selections and u will find a few products that always get mentioned and r a lot of favorites . enjoy