sorry,

that happens if you try to solve these things at work ....

I was looking more for someone with a similar setup and not some general hints.
I can't find any information on the factory supplied radio, so I don't know if they have line in :(

And I'm not an audio expert ... I'm just a geek ... so even if you gavae me all the specs I wouldn't have a clue.

I will go for an external amp ... but I'm still not sure if the KAC will be alright ...

I will choose the speakers after I decided on the amp, but thanks for reminding me ... I would have just forgotten them at all ....

Money:
Well, after buying a $25K car and a $1K "radio" money is the only thing that is sparse ... and I still don't have any seats :(

thanks anyway
ciao
Anti