Possibly in wrong section but here goes nothing !

Is it possible to wire up a small amplifier in my S2 but still using my original head unit ? ive already worked out a way to overcome the remote lead issue by just adding a switched live from the ignition but im struggling with the input side as obviously my 25 year old stereo does NOT have rca outputs on it but i was told a while ago by someone that there is a way around this by using speaker outputs maybe? only looking to get a very small amp that can be concealed behind dashboard to hopefully give my original stereo a bit of a boost! have also uprated the original speakers with some better items but kept standard size etc for originality

Any advice would be much appreciated as usual

Linky below of similar to what im thinking of

http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT