Could you not slot a decent audio in the dash instead, presumably dash fitting kits can still be found if the OE is shaped or double DIN, you'll probably need the correct adaptor plug in kit.

Something like this www.halfords.com/technology/car-audio/car-stereos/...l

I would do this with mine when it fails but its all part of the touch screen system which also controls aircon etc on the LC5, and i know from others who have done this when theirs have failed the wiring involved is a nightmare, way beyond my amateur bodging.