Henk Dijkstra from 
http://www.fastchip.nl/ has adapted the XRD unit to work with the J7T engine and the Siemens/Renix ECU computer. The XRD is a small box with a built in display which - on the Espace - displays the following values from a running engine:
-  Injection time
-  MAP pressure
-  Water temp,
-  Air temp
-  Ignition angle
-  Rpm
-  O2 sensor millivoltage
-  Battery voltage
This is very useful to spy on the engine, or to diagnose engine problems.
More information is available on the web site or by contacting FASTCHIP on 
info@fastchip.nl
(picture from 
www.fastchip.nl)