I have an 05 XT 5 speed and I bought it used with 16000 miles in 07. When I checked the trans fluid I noticed it was on the low side. I checked with dealer and he sold me the Motul 75/90 fluid I use to top up . I notice every 5000 to 10,000 miles the fluid is always back at the low side. What is up with that? Car has 40,000 miles now and at 30,000 I made them change the MT fluid because it was extremely stiff during cold weather. They put the STI fluid in was what they recommended . I checked it after that and it did not use for a long time . Now at 40,000 it was below the low mark . Any thoughts? Is this normal?