tar remover for autos..http://forums.beyond.ca/showthread/t-88197.html
This is what we used at the dealership http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtMxMVlXTVEV76EbHSHVs6EVs6E666666http://solutions.3m.com/wps/portal/3M/en_US/3MAutomotive/Aftermarket/Products/Product-Catalog/?PC_7_0_53BC_root=GST1T4S9TCgv&PC_7_0_53BC_output=html&PC_7_0_53BC_bgel=GSXXHHTMDNbl&PC_7_0_53BC_gvel=WWR6DCKBSPgl&PC_7_0_53BC_vroot=GSLPLPKL4Xge&PC_7_0_53BC_node=GSSPN37QHGgs&PC_7_0_53BC_theme=en_US_aad_portal&PC_7_0_53BC_command=CustomizePageHandler
Skip the 1st link.
Turpentine