I say get a boom box and put it on the seat next to you! Cutting up the body / door panels / dash on a Cobra gives me the willies just thinking about it! Put a nice sound system in other cars/trucks you have, and leave the cobra with the "stereo sound system" it comes stock with: The awsome tunes you get coming out of the 2 sidepipes!
But hey, it's not my car. So, if you HAVE to have a stereo in your Cobra I would tell you this: To get a decent sound (which would be tuff in an open car and the way the cockpit it laid out) you would definately want a seperate amp. The power you get out of the indash is no where near the power it's rated at (max vs cont.) and won't be as "clean" as the power put out by a seperate amp. As stated previously by Jack21, you will need a good pair of speakers. I would also try and find areas to mount them that will be clear of obstruction, ie: not behind the seats but maybe in between the seats seperated as much as possible, up higher on the doors vs down low by your feet, perhaps in the dash somewhere if you don't mind cutting it up, etc. Also go with a CD vs. cassette, or if you have a ton of tapes like I do, at least get a CD changer for the trunk. The sound is much cleaner / brighter.
I have yet to be in a Cobra that had a decent sound system, but I guess anything is possible if you are willing to put the speakers in the right areas, and are willing to drop some tall $$$$ cash!
Just remember, to hear the sound of your radio over the sound of the sidepipes, you will have to have a lot of CLEAN power or it's just going to be distorted. Or, enough power to really pi$$ off your neighbors!
