I have just came back from my local Subaru dealers and he advised me not to fit my Clifford Concept 500 onto a Scoobies, as it interfers with the ECU or something, is this true?

 

I had the 500 installed six months ago to my 93 WRX.

Apart from the aerial breaking (Unable to disarm with remote!) I have had no problems!

 

Your dealer would appear to be somewhat misinformed. I've probably installed Clifford product on over 60 or so Imprezas of every age, specification and origin. The only 'problem' Imprezas were the early Jap-import STi's (easily spotted with their red engine on many models) back in the mid 90's which had some ignition related components which induced rather a lot of power supply-borne noise which could interfere with the processor in some of the higher spec Clifford ECU's. Otherwise, none of the European spec models from the old L-reg right up to present day present any problems whatsoever.

It is not as your dealer suggested, the other way round, in that an alarm ECU can interfere with anything on the car, unless a particularly cack-handed installer (regardless of the brand they use) managed to find some way to make it interfere (-: