Alright so after doing a lot of researching, I've found some info about the speakers in the door of the G37 coupe with bose system.

The door speakers are 10, everyone knows this already. The mid is 3" 4ohms connect parallels with the tweeters, assuming the tweet is also 4 ohms so that would be 2 ohms when they're connected parallel. Now my question is, which brand and model 3 mid is recommended? I've found a few but they're 8 ohms midrange and not 4. I plan to just swap it out and still use the stock bose amp, anyone got any recommendation?

 

MOST car audio speakers are 4 ohm. I see some 2 ohm drivers, but almost never have I seen an 8 ohm driver for car audio unless it's a subwoofer. Crutchfield is a great resource to research. If you choose to buy from them, they have top-notch customer service and quality control. While they sell affordable to high end gear, they don't sell any cheap generic stuff.