Who makes the ups trucks?

Answer 1

Bear in mind that UPS uses a wide range of vehicle sizes. The smaller package cars include Dodge Caravans (presumably the Dodge model.. UPS has their vehicles debaged), Ford F series with a box body, Mercedes-Benz Sprinters (both with regular van and box bodies.. these have also been sold in the past under the Dodge and Freightliner marques)
The "classis" UPS package car with the round headlights were built either on Ford or GM chassis by Morgan Olson and Union City Body. The newer ones with the square headlights are built on Freightliner or Navistar (International) chassis, and I believe are assembled almost exclusively by Union City Body.
As for the tractor-trailer fleet, they use a range of vehicles... Sterling (as well as the older Ford Louisville), Mack, Volvo, Freightliner (the latter two primarily acquired from their buyout of Overnite, which became UPS Freight).

Answer 2

The one you see in the U.S. delivering in neighborhoods are manufactured on a GM or Ford chassis. The older trucks with round headlights were made by either Morgan Olsen or Union City Body. Newer trucks are made by Navistar or Freightliner. Some in Europe are made by Mercedes Benz.