Here is another kit that lets you build a robot car with your Raspberry Pi. PiMobile is ready for Pi 4B/3B/3B+/2B/2B+. It can avoid obstacles and follow lines. You can program it with Swift, Python, or drag & drop blocks.
This STEM kit can be controlled using your mobile device, tablet, or PC. It has all the ports you need to plug in more sensors to extend your PiMobile.