Toyota has historically been hysterical about anybody making any modifications to their cars. They officially recommend against adding/upgrading to an aftermarket stereo. They're that bad.
Toyota does not recommend modifying our vehicles from their original factory specifications. This includes replacing the original stereo equipment with other than what was originally designed for use in your vehicle. Modifications could affect the vehicle’s performance, safety or durability. In addition, damage or performance problems resulting from the modification may not be covered under warranty. For this reason, we do not distribute information or specifications regarding the installation or compatibility of non-Toyota audio systems. For complete details of Toyota's warranties, please refer to your Owner's Warranty Information booklet.
All car companies are the same way. Thank the lawyers. If there is an accident, fire, whatever the first step is to blame the car company and go after them for the big bucks.
Still have my K-10 with the duel fuel tanks outside the frame. Piss pour paint job (undercoating failure) but it runs (about 12 mpg).
Drive the Saturn (38 mpg) most of the time.