ERR3 means the CD mechanism has jammed.
If it's a "top-loading" head unit (i.e. CD slot at the top), then it's quite easy to take it apart, get to the CD mechanism and free jammed CDs. However, with a V plate then it'll be a bottom-loader, which is a nightmare to take apart, so you're going to need a new head unit.
Don't get another Lexus one, they're very expensive and will fail again at some point anyway. Get an aftermarket one as Ormi said.