Be sure to post pics of the 10th scale vent mod, that could look awesome.
Though I've been heavily into hobby-class RC since '93, I've never thought of such!
About the sat/nav unit, are you not afraid of it being stolen? So far in my Miata'ing years, I've lost one headunit & it was a fairly old/cheap one. I also live in a pretty safe neighborhood for that kind of nonsense. But yeah, I've been tempted install similar, but given how easy it is to get into a convertible..
Hopefully I'll be installing my '01+ door panels around the end of the month.