RE: Speakers
I have a 1962 tri-carb, and after reading the other answers, here is what I came up with. I didn't want to drill any holes or clamp anything on, and all I was really interested in was satellite radio. Since I already had a couple of sat radio receivers, I bought a docking station for one of my receivers and mounted it and a cigarette lighter plug on a black plastic shelving board cut to fit snuggly on my parcel shelf (plug toward back, docking station in front). Note that I had already changed to system to a negative ground for this purpose. After wiring the lighter plug, with an in-line fuse, to the hot side of the fuse panel, all I had to do was plug the male plug that came with the docking station into the cig lighter plug to power my sat receiver. I then purchased an Oontz XL wireless Bluetooth speaker and used the connector that came with it to "hardwire" into my sat receiver aux plug. The Oontz is 10" wide by 3-1/2" high, so it sits perfectly under the dash on my transmission cover. I then ran the antenna wire under the door trim and carpet to the back of the car and have it sitting on the top of the top stowage cover under the tonneau cover. The speaker puts out a great sound and is very "hearable" cruising with the top down. I haven't had the top on the car since I've had it, but I imagine I won't have a problem with the top up either. I put connectors on the power wire going to the lighter plug, so all I have to do is unplug the hot wire, remove the board with the lighter plug and receiver and take the speaker out, which takes all of about 30 seconds. Everything is black so you hardly notice its there.