I have been trying to Update and remodel a vehicle that is a single part. when created it was made up of several deffrent surfaces, I have tryed quilting the surfaces together in order to try and get it as a single object so that I can then cut and modify it. I need to remove the roof and have it as a seperate part, but in its current state, I am unable to seperate it from itself. If anyone has any ideas on how to resolve this or need a little more information, any input would be greatly appreciated. thanks.