When will someone make a removeable hard top for my convertible?

Half of it's hard, and there's a glass rear window, is a hard top really necessary?

is it necessary on all the other cars that you can get one for?

never because there isnt a big amount of verts left out there and its not gonna make companies a boat load of money like the miatas and s2k's do

Id estimate 80-100 hrs labor to build a one-off hard top, and you could buy a miata or almost an s2000 for that many hours at a shop rate.