just about anything from the Grumman Iron Works was a good airplane. They built them tough and they built them right.
Grumman also made an aluminum canoe.
I believe they also made the Frito-Lays trucks - look for the Grumman logo on the side near the driver’s door, I think.
The current small mail trucks were made by Grumman. They’ve been around for some time now. It was not designed by Grumman - only built by them.
I dare say Grumman employees would have designed a better mail truck.