Can relate with your situation. Sadly I originally had some online retailers circulate and try to off load faulty sets. I'm sure Real Fx support will help resolve any issues but it's inconvenient and not nice when sets are normally purchaced as a gift for kids.
edit: blue car? Hotwheels set? Real FX cars are Red or Yellow/orange. Real FX Cobalt blue car doesn't ship with the starter kit.
Please let us know who supports what these days.> I cheked the IR sensors with my cell phone camera, but they are working.
This can normally be resolved with a USB calibration tool (sent to you by post), contact the relevant manufacture support department.