Below is a thread where we discussed installing boattails and has the boattail pattern I used for my car. Make a pattern of the tailcone of that aircraft and paste it onto a photo of a side view of your car. If you don't want to chop into your car's roofline metal, just start the boatail curve at the back end of your car's roof.
http://ecomodder.com/forum/showthrea...x-hf-2609.html