Hey CRX guy, welcome to GTPlanet.
Well, you probably made a mistake in typing in the codes. First thing you need to do is go back and double check if every code is typed in correctly.
However, there could be a combination that you used in your hybrid that made the game freeze. You might want to load up just a small number of codes at a time. Sometimes trying to load up multiple codes and cars will make the game freeze.
Let me know.