Just submitted this question to toyota america corporate
"Bought my 01 Tacoma VIN 5TEHN72N31Z836179 this past July in San Diego. I now relocated to Massachusetts and regarding the frame and undercoat I understand Toyota used to offer the undercoats free of charge as a prevention to known corrosion issues. I am wondering if this service is still offered where could the undercoat be done and does that void the extended 15 year warranty that toyota usa offered on the frames for these models. What options do I have? I would prefer it if a dealer had it done it fact but not sure what my options are. Please email or call me. Regards"
lets see what they say! I'll keep you all informed.
btw does scotch guard offer any protection in the meantime?