I got the ScanGauge II mirror-mounted.
BlendMount Mirror Mount:
http://cgi.ebay.com/ebaymotors/Facto...spagenameZWDVW

I got the Add-a-Gauge Model with an extra cable for use on the Saab.

I'll leave it there for the time being until another location calls out to me. It's nice to be able to angle it for optimal viewing. No real mounting and chord-routing issues, though the leading edge of my headliner almost seemed "glued" to the roof metal. I removed the pillar trim, sun visors, etc. to gently pull down the front of the headliner to route the ScanGauge cable through the existing mirror cable hole. I ran the gauge cable through the mirror's spiral cable.