I'm surprised no one, so far, mentioned this. I guess they're too familiar with their 240's and just forgot the obvious.

The arrangement at the bottom of the dipstick tube is unusual, in that when you first withdraw the dipstick, it's always an unreliable indication -- often showing a dry stick. You *always* have to reinsert and then withdraw it a second time for the true indication.

Also, if you do have to add fluid, recognize that there are two vastly different scales based on temperature. You have to drive a lot (higher speed for substantial distance) to get to the hotter temperature; otherwise, rely on the cooler scale if you're just driving around the block to maintain the car for someone who's away; or if you're driving around casually, consider at most some intermediate temperature. Personally, I rely on a IR (scanning) thermometer on the tranny's sump pan, and then interpolate between the two scales for the proper fluid level on the dipstick. *Never*, *never*, overfill -- it's better to err on the side of lower than higher amounts of fluid!
Rolling (VCoA's magazine) published an article that I wrote on this (i.e., interpolating between the scales, using an IR thermometer) some years ago.