Extending a flap door's grip

I am not a pet-person, so we don't have any kind of pets. Kids sometimes are requesting this or that but so far our evasion tactics worked.

In any case, I was in one of these big "pet shops" the other day, because we have moved to a new house roughly a year ago and the old owners installed a flap door on one of the garage doors, like this:

 

As you might recognize the flap door was missing, and the plastic on the outside was pretty worn due to UV radiation. I've decided to replace it so I ended up buying this one:

Although I made an effort to pick the right one, however I failed miserably: I had to recognize that the 4cm width of my garage door is too wide for this kind of flap door:

• the screws were not long enough (quickly remedied by buying a set of M4x80mm screws)
• the two ends of the flap door didn't reach one another, there's a ~2cm gap between the two.

I ended up designing and then 3d printing the missing element. I used Blender for the design:

 

And then printed it via my CraftBot IDEX Flow printer (~6 hours):

 

 

 So the final product has become like this:

As you can see, there's a connecting "tunnel" between the two ends, which I hope would nicely cover the inner insulation of the garage door, both protecting it from the weather and giving us an aesthetic look.

I can't wait to install it :)