I have both the 4 and 8 fin ones. But I got them when I lived in Japan. I think Eagle distributed them. I also think Trinity sold some like it too. The fin does fit with no problems on my car. I just don't like covering up the vent holes in the can. I prefer a fan instead. Maybe I can combine the two...

And for those that don't know Marc Rheinard's LRP Winning setup is posted on RCZone. I'm running a setup very similar to his and it handles pretty good on asphalt in Stock class. I may make a few changes to match his just to see what it does. But I'd also like to try it indoors on our carpet track as well.