Foreign plated car temporarily imported by foreigner:
Original valid driver license
Original TIP (not recommended), copy certified by a Mexican Notary Public better (cost 50-60 pesos) and window hologram on windshield
Original temporary resident card if your TIP has an expired date (not recommended), copy certified by a Mexican Notary Public better (cost 50-60 pesos). Showing valid temp card then shows your expired TIP is valid.
Valid Insurance policy for Mexico, policies from US/Canadian insurers can be problematic as they usually only reimburse in the event of an accident and do not send an adjustor which causes you to go to jail in the event of an accident.
Optional: Birth certificate or marriage certificate or certified copy if you are not the importer but a family member who is driving and you are permanente or a Mexican citizen and you do not have the same last name as importer.
Copy of registration (not needed but some Guadalajara transitos threaten to take car if you cannot prove that the plates you have are the ones issued) which shows your license plate number
Optional: Smog test sticker, usually doesn’t apply to foreign plated cars but those in the state of Jalisco over 6 months are required to comply so if you show your temp card issued over 6 months ago they may ask you.
Mexican plated car:
Original valid driver license
Tarjeta de circulacion and window hologram on windshield
Copy of payment of registration/renewal/refrendo fees for current year
Insurance policy
Smog test sticker
NEVER CARRY ORIGINAL TITLE OR FACTURA IN YOUR CAR. ALSO BE MINDFUL OF KEEPING ORIGINALS IN CAR AS IF CAR IS TOWED OR STOLEN AND THEN YOU NEED SAID DOCUMENTS, WHAT WILL YOU DO? ASSUMING VALET / MECHANIC / CAR WASH / ETC DOESN’T STEAL THEM FIRST IF LEFT THERE.
IF DRIVING A VEHICLE WHERE YOU OR YOUR FAMILY IS NOT THE IMPORTER/OWNER, IT IS A GOOD PRACTICE TO HAVE A WRITTEN PERMISSION LETTER WITH A COPY OF THE ID OF THE IMPORTER/OWNER AS YOU WILL SHORTEN ANY WAITING TIMES IF YOU ARE DETAINED AND THEY ASK IF YOU REALLY HAVE PERMISSION TO BE DRIVING
A good practice is to check the documents of any vehicle before you drive as a roadside traffic stop is the last place you want to learn that there are issues. This also means never assume that if you are legally in Mexico that your status corrects any deficiencies in the status of a foreign plated car, i.e. if temporary import permit expired due to the owner/importer finishing his 4 years as a temporary resident or never renewed his temporary or was a tourist then it will be illegal for anyone to operate the vehicle and will be subject to impound and under extreme cases driver could be charged with contraband tax crimes.