Does any one know how to level up the holosheild quick?

Use it on really hard enemies.

Peace out
Superbird5005 a.k.a The Gamemaster

Let it get hit by enemy fire

Yeah, to go the plant sharr, do the second level, beat up everything in the first area EXCEPT the turrnets in the ground, the ones that can't move, then just use the holo shield so when the turret shoots, it shoots at you, I got mine from level 63 to level 99(its when you get the mega mod of it, it goes above 10) in about 3 minutes

A good way to upgrade the holoshield launcher is to use it on the Endzone challenge. Put an Omega mod on it then make a wall of shields in front of the endzone. Not only will big enemies shoot it from afar, but swarmers will come and run it the shields. It should upgrade from all the action it's getting.

The fastest way to level up the shield is, once you've killed all of the enemies around a turret, set up two shields slightly overlapping. Jump in the turret and blast both of them simultaneously (left turret gun at one, right turret gun at the other). You'll level up approx every 5 seconds.

Go into a huge amount of people trying to kill you. (which is anywhere
You have an arena) set up a circle of holoshields around you. It's
Primo effective. PS holoshield launchers are for pansies.
Hunter mines and quazar turrets.
Now that is a defensive perimeter.
Have fun.
Bye.