Do they really help with what they say they do or are they just a big waste of money?

 

?

 

Already been discussed to the end of the earth and back. Search for the particulars. But in my opinion they may only help if your stock ground system is in poor shape due to corrosion, neglect, or damage, in which case you could simply and economically correct that problem.

 

If you've got a big stereo then it might be worth it to upgrade your engine ground, battery ground, and pos. battery terminal to alternator connection. That's just three wires (and a fuse on the pos. battery connection), no need for a kit. If you don't have a big stereo and your engine runs ok, then no need to do anything.

 

I say waste of money ......you can make your own grounding kit for cheaper

 

And better

 

+1 for making your own.