That won't work with 2.4ghz. Think about it...if you had both radios on and both cars running, which radio would control which car?

You can have one radio with multiple receivers, but you can't have 2 radios controlling one receiver unless you go with an non-2.4ghz (am or fm) radio/receiver. With the old radios, this will definitely work. And that's exactly why most people have moved to 2.4.

Just make sure you have the same frequency for both radios and receivers. But you will only be able to run one set at a time because of the issue at the top of my reply.