ROS Development for Autonomous CAR

We are planning to create a simulation package for an autonomous vehicle with SLAM,Obstacle Avoidance, Lane Detection etc. We have CAD models ready and need to be formulated to URDF . also we have individual packages ready for lane detection, pothole detection etc in python , we are facing problem in integrating them to ROS. Also we are facing problems in integrating Lidar, camera, motor, imu sensors etc into ROS