I finally got around to doing this fluid check. 42 mm at 145F; FSM said 50 mm. Had to get the fluid at the dealership, and they saw me coming! $17.52 for one quart, with tax. And only needed about a quarter quart. Not bad a loss of fluid for just under 40,000 miles (no stains on the garage floor).

New filler cap lock is red, where the original was black. Had bought a couple of spares too.