I would venture to guess that even though they may be similar in characteristics, it is unlikely due to 4 Star being owned and produced by the Florida Motoring group or whatever their name is, and the Sonus line being produced in Germany and is the Autopia's store brand. Perhaps David could clarify that point though.
I don't think the Sonus sline is produced in Germany. I didn't see anything indicating that at the Autopia store. It mentions that it works with German formulations, but nothing about being produced over there.
With the number of private label products on the market, I can see how they might get confused as being the same. I haven't tried either one yet, so I can't offer any opinion based on experience.
I was wrong, I went and checked all my Sonus stuff and it doesn't say where it is manufactured, it just says its distributed by either Perfect Shine, LLC- Autopia, or CMA. I can't check my UGE because I used it up and didn't reorder any.
No advantage, price is the same. I'd say the bottles are the same, but I'm out of the Sonus stuff.
It's the smell that makes me think so the most; that's an unusual scent for a detailing product. It would be very unlikely for two different products to share that scent by chance. It's not as if it's coconut, y'know?
4*'s web page said that the UGE is "only from 4*", so if it were the exact same as the Sonus, they'd be liars. Maybe they are from the same manufacturer, but the proportions are tweaked just a little bit.