Most of the people I know that have tried soaps from all over the place usually end up with Panel Brite or MC Thunder, there are similar products out there and I know a lot of guys that tried the other brands and were not happy so they switched, just like I have.
I went through a lot of brands before I stuck with what works for me, over 14 brands/companies to find some good stuff, kind of like they say, separating the wheat from the chaff.
There are so many suppliers of "truck wash soaps" out there, it is hard to keep track of them all and don't get me started on the "Ratios" that the chemical salesmen lie about when trying to sell you products, way, way, way, way different in the real world of truck washing from what they lie about saying how it will work at this ratio all the way up to this ratio. Most of those people have never washed a truck in their life let alone washed for a living so most of them out there are full of it to put it nicely.
I have a good friend that bought some derby or panel bright or something like that that was supposed to be panel bright but when he told me how it did not work at all, I asked him about it and he told me it looks like watered-down coffee, brown but almost see through. I told him that the real panel bright you cannot see through it at all, even when diluted 2:1 or even at 4:1 with water. I had about a gallon in the 55 gallon mixing drum and added water and with almost 10 gallons of water in it, you could not see through it so that is one test that might help you make sure you got the good stuff.
This is a stronger soap for the tougher to clean surfaces, I don't use it for the day to day or even weekly trucks as I use a different soap for those, this is one of my special soaps and I don't want to waste it on the easy stuff.
Hope this helps.