if you mean the normal USB sockets (got a link ?), for charging your kit, then they're usually wired to a power feed, not the stereo....?

 

Is google broken for your browser??

https://www.ebay.co.uk/i/273428653829?chn=ps

 

Thanks for showing the link Mindriot, that's the switch I refer to. Because the dash has the metal bar behind I didn't know if there were any wires accesible to feed it to without doing some considerable dismantling to the dash and/or removing the steering wheel, and couldn't find any info. Any advice much appreciated. Thank you.

 

Oh I see.

Sorry dont know the T4 that well, the right thing to do is to run in a properly fused supply from a suitably rated source if its just charging sockets youre setting up, either igntion switched live or permanent live, or better both with a changeover switch.

If its usb ports for the stereo you need to access a route to the back of your stereo, and fyi stereo usb ports arent usually very high current rating so they can be a poor source to charge devices. Often the easiest initial course of action is to take the stereo ourt and see what internal access that affords you to route things.

Personally I'd do both, one set for charging one set for the stereo.