Upgrading 1986 911 sound system

[86cabwidebody]

New Guy! Just purchased my second 911. Traded my last one in 1993 for kids and a wife. Now I got one back. Garaged till spring but I am getting her ready.

The sound system seems weak. It has the original Blaupunkt Monterey SQR 23 radio and cassette deck at an astounding $657 on the original window sticker! Speakers appear to be paper. 3/14" between bracket holes in back and 4" in front.

At that cost the unit must not be the cause?

[B]What is the best approach to upgrading this system without any new holes in my all original? I would like to have ipod capability.[/B]

I have an fm transmitter for the ipod I use occasionally with a boombox, but a more direct link without batteries involved would be nice.

I want to keep all the original stuff and ideally be able to, as easily as, possible reinstall whatever I change.