Pontiac Repair: Bonneville Radio signal, fm antenna, razor knife

Question
I have a 2003 Bonneville SLE with the antenna for the AM radio I think in the back windshield. I have a hissing or whistling sound when I listen to AM radio, FM is fine but the FM range is limited, how can I install a regular AM/FM antenna on the trunk hood, and link to the old antenna wire behind the back seat?The sound with the AM radio started when I paid a shop to tint the glass, however, they have gone out of business, which is good for other people. Thanks

Answer
To install an antenna, you'll  need to (obviously) find a place for it, and drill a hole for the cable to pass through.
Better than that, and maybe cheaper, if you have a good automotive electrical shop, they can /could find the breaks in the antenna and solder them together. PROBABALLY the tinter cut the antenna with a razor knife or somerthing like that. Just tint wont make poor reception. You may also check with a GOOD auto glass person, they too may have experience in repair of antenna.
Thats just advice. I am not a big fan of altering the OEM set up.
If you do decide to install an external antenna, check with a body shop or body customizer in your area for advice/work.
I hope this helps
Good Luck
God Bless
Pawl