Yup, thats the problem with the Aventador kit, theres no glass available for it. Autotemp can make the side glass for you, its 1K to do the set-up, and then about $80 per piece of glass to produce it. For the front windshield, its about a 5K set-up charge, and then each windshield would cost about $300.
Dont even waste your time with a template at the junkyard, there is no donor in existance that will even be close. The Aventador windshield is about 6" longer than the Murcielage windshield, the Maxima donor we use will be way to small in height and width. Same problem with the sides, the Aventador side glass is 4 1/4" longer than the Murcielago, and 14" tall with a compound curve. There is no donor even close for Murcie side glass, same with the Aventador.
This is the main reason I wont do an Aventador kit, along with there are no interior pieces availble for them either.
I hope you have deep pockets, or are not in a hurry to finish.