I am trying to mimic your look but i was told dip armour mid coat then dip armor kit is the way to go to protect from scratches and all. Have you considered dip armour? Unsure if mine wont look likes your with satin or matte finish but dip armor seems the way to go and you cant i been told use dip armour on matte or satin.
I've never used Dip Armor, but seems like a good product with tradeoffs. It also seems to change the properties of "dip." Yes, it hardens it such that it's more resistant to scratches and chemicals/fuel, but it is not impervious to them. For example, in the DYC videos, it seems gas will still stain it, just not as badly, and only if you are Johnny on the Spot to wipe it up and flush it with water? It will make it more scratch resistant for sure. In exchange, I believe the peel-ability suffers. You have to sit it out in the sun to heat it up, and use isopropyl alcohol to get the thinner areas. I don't even know how touchups and repairs would go.
And I agree with Ostrichsak. One of the purposes of a wrap, is to change the color of the car, but also give it some added protection. In my opinion, it seems silly to pay more to make a temporary by design coating less temporary. Now if it were a negligible price difference, sure why not? As you can see from this thread, I don't keep the same color too long, so dip armor doesn't make sense for me at the additional cost. Not to mention, I've moved over to Raail's products.
If you like the satin look of dip armor, that can be achieved with more coats of clear for more of that "gloss-ish" look. Raail's AirWrap is also more satin by default.
Also do you believe medium size for carbon pearl is enough for a model 3 given all glass top?
The rule of thumb is always order if you are in doubt. More product laid down, just means an easier time with removal later. Also, if you finish up your final coat, and have a little left over, that's for repairs if you ever need them. But, to answer you question, yeah I think a medium kit should work. I think I ordered a medium kit for my S, so it should be enough for the 3.