A few years ago I posted some pictures of a storage rack I built for my hardtop. A couple of days ago I received a PM asking me for the measurements. Since I'm not technically savvy enough to figure out how to insert pictures in a PM, I thought I'd just post everything here in case anyone else would like it.
As a caveat, I am not an engineer, carpenter or draftsman. This worked for me but I can't guarantee your results.
I saw a picture somewhere on the internet of a similar rack for another car, maybe a Honda S 2000, and it was made from PVC plumbing pipe and joints. I thought 2 x 4 lumber would be a little easier because I was doing it on the fly and might need to make adjustments. So mine is made entirely from 2x4 lumber and screwed together with long enough deck screws. This rack has been used in 2 different houses, it is screwed to 2 studs spaced 16 inches apart and has never caused me any issues. The top stays in place unsecured, but I put 2 eye screws in the sides and use a rope to prevent it from tipping forward. I stapled foam plumbing insulation over the portions of the rack that come in contact with the hardtop.
It does require 2 people to put the hardtop into this rack and take it out of the rack to put it on the car! One person can't do this by themselves like people do with ceiling hoists.
I should have used a framing square as I went along. I didn't, and it isn't square but it works fine. If I were to do it over, I would use a framing square.
If you want a cover, do a google search for hardtop storage cover and buy the cheapest one you can find that you think will be big enough. A few years ago when I bought mine, I bought one for a Maserati TC by Chrysler because it was plenty big enough and it was dirt cheap.
So here are the pictures and my non-draftsman drawings. I'm sure there are folks on this forum with far greater carpentry and design skills than I have. Feel free to take this as a starting point and improve it. If you have any questions, ask and I'll try to answer.
Note: in the picture below, the 17-1/2 inch depth should include the full depth, from the front edge of the stub upright to the back edge against the wall.
