Hi ACMethod,
Any name brand one would do. You'll have to take it apart and wire it in unless you just stick it in the cig lighter socket and do it that way. Mine's under the center hump console. Just don't use one that's 5.00 from Walgreens or Ebay. Use something reliable and moderately priced. I don't remember what mine was from. I took apart a BT to Stereo receiver and used the 12 to 5 converter from that. Just wired in etc.
I used an inline micro USB female to 30 Pin adapter also, that's important and I forgot that in my first post. I don't remember that either.
I just searched for half an hour and couldn't find one. It's a 30 pin female Apple on one end and a 30 pin male apple on the other. It has a micro usb on the side to inject the 5V from the 12 to 5 adapter that powers the WMA on immediately when the car turns on so the WMA can be found by the stereo. Mine works flawlessly. I'm sorry I can't recommend where to get that type of connector now. It was years ago when I adapted mine this way. 30 pin to Lightning is all I can find now. if I dig something up I'll let you know.
http://dock.miuirussia.com/30-pin-dock-extender-cable/
Not the extender cable but notice the female to male 30 pin adapters, like those but with a micro usb female jack to inject the 5V to power the wma unit.