http://yucalandia.com/driving-in-mexico-issues-fun/adunana-t

http://yucalandia.com/driving-in-mexico-issues-fun/adunana-temporary-import-permit-tip-renewal-form-nov-2013/

Aduana now accepts an official request form and instructions for foreigners to report changes or expiration date renewals ~ by mail ~ . We thank Ric Hoffman for supplying this very useful information, for people who don’t have an Aduana office “down the block” – (and for those whose Aduana offices are less than friendly/helpful).  Readers who want to renew/extend the expiration dates on their vehicle’s Temporary Import Permits can use this form and mail it in directly to Aduana DF, to get their permission letter.
You have 2 options: Ric created a good .pdf file if you want to use it : New Aduana Aviso for TIP or cut and paste the form listed below. The pdf file is set up to be completed by cut and paste operations. This pdf version is also set-up to default print 4 copies of only Page 1. In both forms, the second page has the instructions in Spanish and it is fairly easy for non-speakers to figure out. (If not, cut the instructions from the text below, and copy them into Google Translate.)
Filing Instructions: Articulo 19, Manual for Importación temporal vehículos 2012, instructs us to mail these forms directly to the address listed without a local Aduana Stamp, if you do not live near an Aduana office. Ric added this formation as the last paragraph on the instruction page. The other paragraphs, (referring to the “Aduana Stamp”, on the page), are from the Aduana office in Lázaro Cardenas. If you notice, even after you have the Aduana Stamp, you are instructed to mail a copy to DF. Once received in DF, they will send you a confirmation letter. Readers interested in seeing an example of a redacted confirmation letter (to carry in the car) can check out (a 3 Mb file which may load slowly): Aduana Permiso Approved Letter_Redacted

http://yucalandia.files.wordpress.com/2013/11/aduana-permiso-approved-letter_redacted.pdf

http://yucalandia.files.wordpress.com/2013/11/new-aduana-aviso-for-tip.pdf