I just recently bought a 2014 Chevy Cruze. No trans filter, no dipstick but its just about the easiest vehicle since my Duramax with the Allison trans to service. I have drained and refilled the trans twice with the drain plug on the bottom, simple as draining the oil. The first time I did it I filled it back up with the approximate amount that came out and pulled the fill plug on the side to check it. Topped it off until it ran out which confirmed it was full. Second time I drained it I measured the amount of fluid that came out by pouring the drain pan contents into a 1 gallon jug. Came out to exactly 4 qts which is what I put back in it plus a few ounces for whats left in the drain pan. Like you I thought it was stupid to do away with the dipstick but in actuality it ends up being simpler. The Dex VI isnt likely to vaporize away and as long as there arent any visible leaks its all good.