Yeah! I've installed quite a few car stereos over the years, and I often have to remove a dashboard panel or two. The company "Crutchfield" has these free guides of how to do it for every car, they might even send you one if you aren't a customer, since their service is amazing.
Once you know where to pry, it is just a few minutes to click off a panel, then 2-4 screws to release the radio, then a few more screws to take off its cover. Once you have its cover off, the penny will probably be sitting right there near the top.
One more possible trick: are US pennies magnetic? I remember the Canadian ones were. If they are, fishing around in there with a strong skinny magnet might do the trick. I have a screwdriver with an extendable magnet tip that looks like a car antenna.. you can bend it around and poke it into awkward spaces to retrieve stuff.