Car Seat?

So far since I've turned 2 years old, we've tried out a few different strategies for how I fly. Up until a few months ago, I had been perfectly content sitting on my parents' laps with the occasional flight where there would be an empty seat in our row for me to use.

Now that I have to pay for my own seat, my family has tried (a) bringing a child car seat onboard, (b) hoping I sit still without a car seat, as well as (c) continuing to sit on my father's lap the entire flight. I'm still not 100% convinced there's a way that I prefer over the others, but sometimes logistics dictate more than personal preferences.

For example, our flight down to Austin a few months ago, we had to make a tight connection in Charlotte, so checking our car seat would have been taking the risk that it didn't show up in Austin's baggage carousel when we absolutely needed it to drive an hour to San Antonio. So in that case, we lugged the car seat through the airport and brought it on board to secure to my window seat. On that same Texas trip, but on another flight, we called an audible since I didn't want to be strapped down. Instead of losing our 3rd seat to an unused car seat, we went to the flight attendant and asked to gate check it at the last minute before the boarding door closed.

And now, tomorrow we're flying trans-Pacific non-stop to Hong Kong. While it might be nice to have a car seat with us on board to alleviate my parents from having to hold/watch me the entire 16 hour flight, we really have no need for the car seat at all while we're in Hong Kong given the abundance of efficient and cheap public transportation. And if I again decide I don't want to sit in a car seat on the plane, then we'd just lose the use of that 3rd seat because there's no where else to store a car seat once we've taken off. Of course, not having me strapped down while my parents sleep for 5-7 hours could be problematic also, as I've been known to try to get out of my seat and wander down the aisles when they're not looking. Of course, that's in addition to the off chance of strong turbulence thrusting me out of my parent's arms and helplessly into the air.

So what should we do? I know most of my readers usually look to me for child travel advice, but I'm open to any ideas or suggestions.