You guys might wana try the Cool Can Fans. This produsct has 2 fans sitting over the motor and the brush hood and can also be used inconjunction with brushless motors on a carbon fibre bracket which matches the carbon on your (within reason). What you don't want to do is have any part of a product physically touching the motor (other than the products that you remove prior to racing), so as to block any air vents there maybe in the motors, also damaging any lables, timing marks you have on the kans and hoods. The CCF is a stand alone product which is mounted onto existing fixings within the car, so there is no need for any cutting, filling, removing of any parts of the car whatsoever. We have found that it is far more benificial to extract the hot air from the motor kan, and to blow cool air onto the brushes to stop fade. We have sold in the region of 2,500 CCF kits to date and we have all the models to date for these kits and if not we will endevour to make them to order. I do hope this helps answer any of the heat issues, if you want ask and questions I would be more than welcome to ablige.
Cheers Malc TCFM