Next time you're in a P-38L do this to find out if they do have dive flaps.
Before you start you dive, open your canopy using Alt+F4 and gingerly unbuckle yourself (don't roll as you'll fall out of the plane). Engage the dive flaps. Next, stand up but be sure to make sure you've got goggles on and keep your mouth closed (bugs flying in your mouth is gross). It's going to be a little windy, so you might want to dress appropriately. Now, lift one leg out of the cockpit and set it on the wing. Do the same for the next leg. Now you're standing on your wing. Gently lower yourself so you're crawling on all fours and shimmy to the leading edge of the wing. Now remember you're in a high speed dive so hold onto something firm or you'll be blown off the wing. Now, look under the wing and you should see this little flap thingy deployed under the wing. Those are the dive flaps on the P-38L.
In all seriousness, you're a clueless squeaker so of course you're not going to know that you need to disengage combat trim or the dive flaps won't work properly.
ack-ack