I have a 2003 volvo s60 2.4t that i want to have little bit of rumble when i step on it but nothing to loud when cruising. What do you all suggest i do? what is the stock exhaust inlet pipe size? could i clamp a muffler?

 

Does your model have a center resonator? If it does, have it removed and replace it with a straight pipe. It'll make the done on acceleration a little more noticeable and slightly deeper. I had it done to my S60R and it sounded great and only cost me about $50ish IIRC.

I don't know the OEM exhaust size, sorry I can't help there.