I installed backup lights on the back of my truck. They are very bright but they do not spread the light that well. I was wanting to diffuse the light and was wondering what you guys would think the best method would be. I could not find any relevant info online. I put masking tape over the bottom half of them and it worked fairly well despite a big drop in brightness but after removing the tape there's road grime caked on the fog light. The fog lights are Chinese knock offs of rigid dualilys but they work good for the purpose. I'm gonna try frosted shipping tape and see if that works. If anyone has ideas feel free to share

 

I know this is a few months old, but figured I'd try to help. It sounds like your lights are led spot lights, where for backup lights you should have looked for flood lights. The floods are designed to disperse the beam. I just ordered these myself:
You can choose flood or spot with these

 

I'd say replace the lense but the only company I know that lets you do that, is Baja Designs.

I sell lights, pretty inexpensive, from AuxBeam that come in various flavors. Spot/Flood. I use the flood kind for reverse. PM me and I'll point you in the right direction.

 

I currently have the flood version of those lights but they are a different brand.
My issue was despite them being a flood light they didn't spread light good enough for a reverse light. I was looking for something to diffuse the light better like what is installed on the diffused rigid duallys or other fog/headlights.
I have taken shipping tape and scuffed the surface with sandpaper, to diffuse the light. This works ok but it isn't a great solution, imo

 

Scuff-sand the lights' lenses directly. Forget the packing tape.

Like you said, you bought cheap knock-offs. So you shouldn't be afraid of scuffing them up on purpose if you do the right prep work and work patiently at it.

 

You probably work for the company. You've replied to a lot of threads that don't even talk about things like this posting the same info...

SPAMMER ALERT!

(this post was in response to a spammer posting all his amazon links... looks like the admins deleted his thread though)

 

Are you throwing this accusation at me?

 

Nope not you... the guy must have either deleted his post or an admin did... some guy was responding to every thread on here with his amazon links... guess they got rid of him.

 

These spam bots are a pita. I'm surprised I didn't get a notification email, I'm subscribed to the thread and it always sends me alerts immediately