I didn't have room to mount the esc flat to my chassis so I made vertical brackets from Al strips and secured them to the chassis through some rubber pieces (to give it a little shock absorption). The esc is the same length as the 1527 it runs next to - so it's right at 4" long. I didn't have any problems with temps last summer in 80-90F weather (see back a few pages) so I didn't bother with a fan.
I haven't yet cleaned and rebuilt the back half of the truck yet, which you can see from some of the dirt in the pics.