To import a used vehicle into Mexico, it typically requires:
* The vehicle must meet Mexican emission standards. Older vehicles generally do not.
* You'll need to pay import duties and taxes. These can be substantial.
* The vehicle must undergo a rigorous inspection.
* You'll need proper documentation. This includes title, proof of ownership, and other import paperwork.
* It might be subject to a temporary import permit, with limitations on how long you can keep it in the country.
Importing a used vehicle older than a certain year (which varies and is often much newer than 2001) is usually not permitted without significant hurdles and potentially very high costs that might exceed the vehicle's worth. The process is complex and often involves specialized import agents.
In short, while technically possible in some extremely limited circumstances (such as through a temporary import permit for a limited period), legalizing a 2001 Chevy Silverado for permanent use in Mexico is highly improbable and likely economically infeasible. You'd be much better off buying a vehicle already registered in Mexico.