It depends on a load you're putting on that wire. Be careful with it
'cause you can easily burn fuse, or, God forbid, start a fire.
Cheers,
Voja
On my (USA) 2005 Forester, the Subaru manual states the following:
* The electrical power socket located on the lower part of the
instrument panel is originally designed to use a genuine SUBARU
cigarette lighter plug. Do not use non-genuine cigarette lighter plugs
in the socket. Doing so may cause a short-circuit and overheating,
resulting in a fire.
* If the socket is ever used for a plug-in accessory such as a cell
phone, that may damage the portion of the socket's internal mechanism
that causes a cigarette lighter plug to "pop out" after its lighter
element is heated. Therefore, do not place a cigarette lighter plug in
a socket that has been used, even once, to power a plug-in accessory.
Doing so may cause the plug to stick and overheat, creating a
potential fire hazard.