Replacing a Punto cassette player with a CD

[PeteXXX]

Hi,
I have recently bought a Mk2 Punto Active (53 plate, Sept 2003 with no stereo controls by the steering wheel) that has the Blaupunkt cassette player in it. I tried swapping it with an LG CD player but it didn't work and the car would turn over but not start. No dials on the dash worked. Put the old one back and all was OK, apart from the fact that it still a cassette player!!
The top pics are what I have now and the last few are what I tried replacing it with.
There is nowhere to plug the blue/green/yellow block into on the LG.
I've seen a converter cable (bottom right) for a few quid. Will this do any good?
Any help appreciated please.

 

[Palmerino]

Try the Punto section, they are most likely to have the knowledge and more people are likely to see it.

 

[PeteXXX]

Thanks, I'll post it there