See also:

Accessory installation
We strongly recommend that Volvo owners install only genuine, Volvo-approved accessories, and that accessory installations be performed only by a trained and qualified Volvo service technicia ...

Replacing the batteries
CAUTION When handling batteries, avoid touching their contact surfaces as this could result in poor battery function in the remote key. 3 Note the position of the battery's (+) or (–) sides. ...

Severe strain on the brake system
The brakes will be subject to severe strain when driving in mountains or hilly areas, or when towing a trailer. Vehicle speed is usually slower, which means that the cooling of the brakes is less ...