I installed boost, oil temp and oil pressure gauges in the RX-7 during the week, pretty staighforward job. The gauges should prove useful in terms of indicating whats going on under the bonnet.
I ended up installing a DIN style gauge holder. Between dials, oil filter sandwich plate and gauge holder (all off ebay), I ended up spending about €160 - very good price I reckon.
Hose and sender cabling were fed thru the main harness grommet in the firewall while power (switched and lights) was taken from the cig lighter.
Reckon I'll get some gauges into the FTO on the near future, oil temp and pressure would be useful for a start. I might even stick in a second water temp gauge, the stock unit on the FTO isn't particularly accurate in my experience.
CJ