phone

So, I was wondering if an International SIM Card would possibly work in a 2005 Maserati QP phone system? I see there are a few for sale at Amazon and Best Buy that are universal GSM Sim Cards and work in 200 countries. Has anyone had success with this and/or tried this to get their phone to...

I have a 2005 QP with the phone installed. it has always worked great. Today for some reason the volume has dropped way down. I have to crank the volume up so high to hear even the slighest voice on the other end. Has anyone come accross this issue? Thanks in advance