I added an external filter in the return cooler line.
So, this filters the oil and the internal filter which can only be replaced on a rebuild I dont have to worry about. By the way Carquest sells a filter specific for this, BUT I used a 3/8 input large metal can fuel filter from autozone and it worked just fine. Thousands of miles later the fluid is still clear and red. Think of it like this, gasoline has more solvent action than ATF and the gas filters to at least 10 microns or better. And these filters have to take high pressure without exploding, which by the way, the retrun line does not have a high pressure. Just dumps into the sump I think.
I also added an external oil cooler made for a ford focus, fit in with very little trouble. I installed the external cooler in the return line and then it goes into the filter and then it returns to the transmission. There have been no flow problems even in cold weather.
