Just drove the 'school bus' run (20mile round trip) w/ the SG2 and here's my quick report.

The ODBC port is tucked to the left of the center console just below and to the right of the steering column (kinda hard to find, but easy to leave connected while driving) I placed it on the shelf behind the gear shift.

The code reader seems to work (no codes), the Gauges appear to work accurately(RPM, temp, etc), but the trip/MPG display seems off quite a bit. The sampling rate is immediate (the right-now reading is...) so I saw between 24 and 2347 on the MPG display. Of note, when coasting in my 03 Si, the MPG would spike to 9999 (max) on the display. While driving the hybrid, the MPG would read between 55 and 58 and the instrument panel gauge read 52.3 the whole time.

I'm partial to the instruments as they show a moving average over a period time, not a dynamic "right now" reading. I'm thinking I'll leave it in my Si till I have codes to read.

Four-passenger, stop-n-go, schoolbus-commute.
Just arrived, "Electra" the 06 HAH... yes, now we're a two hybrid family.