Well this is where I was when the server went down several days ago. Since then I had to go out of town over the weekend and returned to put two days on car construction. The neat thing about C9x's HAMB post is that is is mainly about roadster seats BUT also shows his battery box. In the meantime I have been fooling with the gas tank question and I have used DennyW's idea about some sort of armour plate. The rumble hinges on the Bebops body has two vertical plates to stop the hinges when the lid is flipped back. I have attached a 1/4" thick 4" wide steel bar across the rear of the rumble area just inside the seat area and 4" behind the back edge of the tank so that in the event of a rear collision the rear bumper will be augmented by the 4" wide steel bar and if it is bent it will have to be bent in at least 4" before any contact occurs with the tank. I am negotiating with Rock Valley to fabricate a tank of about 16.7 gallons capacity. Then I started work on a battery box to be mounted in a similar way using a heavy duty battery box from Speedway. I have measured several batteries as to height and 8" will do for batteries with side connectors but the top edge of the battery box hits the frame bottom in such a way that the battery bottom will be 9" below the top edge of the frame. I have looked at the HAMB picture C9x posted and see that his battery is at or above the bottom edge of his right rear four-bar and that will be so on my frame as well. However, it looks very low to me. Considering that my clearance on the front axle is only about 4 1/2" I guess on a level road the battery will be above that but if the right rear wheel goes down into a gulley or deep tire track it looks like my battery box will take some grief. I had no intention of running the Baja with this car but this clearance limit is just one more limitation to a boulevard cruiser.
I am also reading the HAMB posts from C9x on Caravan seat mounting so this thread is about roadster seats, gas tanks and battery boxes now I guess.

Don Shillady
Retired Scientist/teen rodder