CRD OPTIONS,,,,,Scan Gauge,,,,,,,RE-MAP ETC ETC

My mate has just purchased a 2013 CRD 3ltr auto wagon, I have advised him to buy a Scan-gauge.
What other options are available using the OBD2 port. He will also be getting a re-map later on, as IMO
I think there is more bang for buck value going that way.
The Patrol only has 40k on it and a 3" exhaust.
The patrol he brought before this was EX Telstra wagon DX 08 which gave him nothing but trouble.
The last straw came when they told him it needed new injectors $$$.