By way of update and info guys, I bought a "guaranteed compatibility" kit from In Car Emporium's ebay shop. Pioneer mechless head unit and Kicker speakers. They provide the wiring, the security keys to remove the original unit and radio antenna adapters so everything slotted into place without any cutting or screwing.
It sounds excellent, I have to say and the tweeters on the top of the doors are still working too, along with the electric aerial. The only issue I had was that the stereo unit did not seem to have constant power to maintain the memory so every time I turned it off and removed the ignition key it basically died, meaning that the next time the key went in, the unit thought it was a first-time installation. I called ICE and they explained that it is a very common problem with Pioneer head units and that I needed to remove it again and find the bullet connectors in the power side of the wiring adapters behind the unit (there are two connectors, 1 for power and the other for speakers and the power one was labelled so easy to identify). The red and yellow power leads needed to be swapped round so that the red went to the yellow and vice versa. I made the change and hey presto, everything works as it should.
Recommend this unit and worth the extra for the fitting kit and after-sales support for a non-mechanic like me
