Hey, I am about to do this on mine. Had it installed on the vw equivalent stock HU called a gamma. Just a 2x pre out lead with remote I/O cable needed. Works really well, and actually stopped me buying an aftermarket HU on my lupo & polo. It takes a lot of the low range stress out the speakers and works generally well. Of course an after market will be better, but i don't think, unless a really top end one, will look as good either.
Leads are cheap too. Would recommend this for sure!