[Christ]

I wanna turn my 96 Passat sedan into a 'fastback' style car... but I suck at angles.

I know the average best rearward angle is 12* tapered, and I can set a solid 12* angle, but how do I measure the taper properly?

I planned on making a removable rear 'housing' with brake line [or framing wire or something] and then stretching cloth over it and soaking that in resin to solidify the shape... if I decide it's worth while, I'll make a full FG version and probably set it up with hinges and seals so i can remove the back window entirely and mold it to the lower portion of the trunk lid.