Your vehicle's suspension and underbody can be damaged if driven on rough/uneven roads or over speed bumps at excessive speeds. Use care and reduce speed when traveling on rough/uneven roads or over speed bumps.
Use care not to damage the vehicle's underbody, bumpers or muffler(s) when driving under the following conditions:

This vehicle is equipped with low profile tires allowing class-leading performance and handling. As a result, the sidewall of the tires are very thin and the tires and wheels can be damaged if driven through potholes or on rough/uneven roads at excessive speeds. Use care and reduce speed when traveling on rough/uneven roads or through potholes.
Overloading
TowingMazda 6 Owners Manual: Parking brake (lever type) removal/installation
1. Remove the center console. (See CONSOLE REMOVAL/INSTALLATION.)
2. Remove the rear seat cushion (4SD) or rear seat (5HB) . (See REAR SEAT
REMOVAL/
INSTALLATION.)
3. Remove the exhaust pipe bracket.
4. Remove in the order indicated in the table.
5. Install in the reverse order of removal.
6 ...
Mazda 6 Owners Manual: Operational Range
The system operates only when the driver is in the vehicle or within operational
range while the key is being carried.
Starting the Engine
NOTE
Starting the engine may be possible even if the key is outside of the
vehicle and extremely close to a door and window, however, always start the ...