I found (through experimentation) that with the engine cold the trans fluid level is in the 25 Deg. C range. With the engine warm (30 minutes of driving) the trans level is in the 80 Deg. C range.
You will also need a new plastic key tab to lock the dipstick cover in place (the old one must be broken to remove it).
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles