Ultimate radio reception fix?

[PaulDash]

My radio reception has always been horrible. Doesn't matter if it's AM or FM. Doesn't matter if it was the stock CD-22 or the Becker Indianapolis Pro that I put in to keep the stock look and have a Bluetooth phone hookup.

This month, the Box is going to get some new Alcantara upholstery (separate thread coming soon). This means taking apart the entire dash, A-pillars, et cetera.

My car has option code 618 - Preparation for telephone installation. I'll obviously never be putting in a 15-year old Nokia GSM module in there, but I do have a little antenna sticking up from the top of my windshield frame. Here's what I'm thinking...

Would it be possible to replace the little GSM antenna with a FM radio antenna and connect that to the antenna amplifier? Should this improve reception? Will there be any problems with interference with other cabling going up the A-pillars? Finally, will I ruin my resale value because I've effectively removed option 618?

Looking forward to all constructive feedback.

I'll post photos and write-up of the project if I do decide to go forward with it.