355 replacement speaker ideas?

Does anyone have any recommendations for replacing the stock door speakers in my 99' 355 Spider? The replacements need to drop in with minimal alterations. I would like the car to maintain the doors stock appearance. I currently have the Nakamichi cd-400 receiver and an ads p640 amp. I'm not looking for a super high end system, just an improvment vs the factory unit. Yes, I prefer the engine music to the stereo...but sometimes a little stereo music is welcome (Please don't hurt me for this moment of honesty!). Thanks, Tim

 

Thanks! Tim