has anybody used this in their car.

I have not switched yet, but looking to once I get the trans swap done again. Here is a shop that I take my vette to that has used it in various customer vettes and bikes. Might be able to give you better hard numbers. Especially since vettes are even harder to keep cool than the chevelles.

http://xmsengineering.com/index.php?main_page=page&id=5&zenid=9c5870d181bb4005debc76e42a727934