just fitted 2 nice big chunky golt battery terminals to the z and what a differene they made :D i've now better turn over and it's to the poin that with the standard terminals when i turned the car over it would take the power from the stereo but now it dont would have taken some pics but my camera batteries are flat if i get chance i'll do some tomorrow

Have you fitted an earthing it too?

yup put both terminals on only £10 each from motorworld

One of mine came with my grounding kit, they work well.