The Ford radio is probably a 5000 or 6000 series head unit, which has an ACP bus. It doesn't have line in & as far as I know there aren't any line in adaptors available :(

You could try asking autoleads (www.autoleads.co.uk) who supply mounting plasticwork for the Puma, and also a Sony bus adaptor - it may be possible to use this adaptor as a line in unit, as Sony changers have RCA outs. There's not room to fit both head units in the dash, though!

Hugo