My best friend and I just installed a supercharger in his '02 Mustang gt with a sick blow-off valve.
I was wondering if a BOV can be installed on the supercharger of the '03 c230

BOV's are not needed or useful on a properly designed supercharger system. You car has something similar called a bypass valve. The purpose of the bypass valve is to dump the boost when operating at idle and part throttle conditions. The reasons for this include improved fuel economy and less wear on the supercharger. You can add a BOV if you want.

Thanks for the response Lynn, If I was to add a Bov, would it make the sss noise or is there not enough boost? Also, would it lower the amount of air that is being produced, therfore lowering my hp?

I don't know how much sound it would make. You car has 11 psi max boost from what I have heard. There was some one on another board who changed the bypass valve so it dumped to the atmosphere instead of back into the intake hose. He claimed it made the proper sound, but it wasn't very loud. He had a 2.3 so he had 5 psi of boost.

Thanks Again Lynn. Do you have any idea wich BOV to use? or Should i go for a universal BOV.

I have no idea what BOV you should buy. I don't recommend buying one at all. There are better things to buy for your car. But it is your car and your money, and I respect your right to do as you wish. Good luck with it.