I completely understood what you want and it could easily be done by using OpenCv and yolo(especially designed for detection of Vechicle).
I have 3+ years of experience in Image Processing, Machine learning, Deep learning and 5+ years of experience in Python.
Also, I already worked on such kind of projects such as Object Detection, Vechicle detection and many more.
So,if I would get a chance to prove, I will deliver this to you within 2 days with full of your satisfaction.