Change licence plate on car

Every shot with the license plate needs to be a separate composition. Some will require rotoscoping. If you have the original footage without the dissolves you will need that because replacing the license plate with a dissolve is going to be really difficult.  The first shot is probably using a workflow I call Stabilized Power Pin.

You'll end up with something like this:

And that will turn into this:

The second shot has no camera movement, Rotobrush probably won't work but you can just add a solid and do some manual roto then use that as a track matte to hold out the running kid. I turned on the track matte so you could see how the blend mode makes it easy to see through the solid layer and so you could see all the keyframes.

Shot 3 and 5 might not need fixing. If they do, the license plate is so far away that just tracking in Mocha will probably be fine. You're going to need to do some track mattes though.

Shot 4 and 6 will just require corner pin tracking using Mocha AE. If I had the original shots I'd budget a day to fix the shots. 

Hope this helps.

You need an image of the Swedish plate, just a simple flat front shot.

The replacemant should work good with Mocha. You can track the plate and insert the image. All movements and perspective changes should be covered by Mocha.

The one static shot with the kids in front of the car needs a moving mask. You need to rotoscope this one. AE should offer a good roto tool for that.

*Martin

A conventional corner pin track in the shots where the plate is fully visible will suffice. You may need to use mochaAE for better results, though. Since they weren't specifically prepared with tracking in mind, many of the shots are quite jittery. Just be prepared that this is going to take a while due to the extensive masking required in some shots. It's more likely that you're going to step through the tracks frame by frame and need to tweak it a lot instead of just letting it zap through and be done, but of course you will have to do the masking either way.

Mylenium