OMG I found it! Police Hauler mod for GTA 5! I compared it with Normal Hauler, did some cars tests to find out which truck is best.
Let me know which is best for you and which GTA 5 Mods to compare next?

Police Hauler (ELS) by emtp211
JoBuilt Hauler 270 by Monkeypolice188

Music:
Monkeys Spinning Monkeys by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song...
License: https://filmmusic.io/standard-license

Amazing Plan by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song...
License: https://filmmusic.io/standard-license

Run Amok by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song...
License: https://filmmusic.io/standard-license

Jaunty Gumption by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song...
License: https://filmmusic.io/standard-license

The Cannery by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song...
License: https://filmmusic.io/standard-license

Call to Adventure by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song...
License: https://filmmusic.io/standard-license

There It Is by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song...
License: https://filmmusic.io/standard-license