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.
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TowingMazda 6 Owners Manual: Scheduled Maintenance (Mexico)
Follow Schedule 1 if the vehicle is operated mainly where none of the following
conditions apply.
Repeated short-distance driving
Driving in dusty conditions
Driving with extended use of brakes
Driving in areas where salt or other corrosive materials are used
Driving on rough or muddy ...
Mazda 6 Owners Manual: Dual proportioning valve inspection (without abs)
1. Connect the SSTs to the brake pipes as shown in the figure.
2. Bleed the air from the brake system.
3. Measure the fluid pressure of the master cylinder and the rear brake.
If not within the specification, replace the dual proportioning valve.
Fluid pressure
...