Not sure why I would do that, but just a random thought.

Let's say I'm almost out of wax A. Does it matter if I pour the remainder into the bottle of wax B?

We can mix Coke and 7up together, it's still soda.

Does mixing two different brand of wax create something that is not safe to use?

 

Wax is wax is wax. You can go as far as to mix a sealant with a wax if you wanted to. There'd probably be no beneficial result, but in the end it's still hydrating the clearcoat and providing UV protection.

 

are you talking about puting a coat of wax over a coat of wax? or using two waxes to put one coat of wax on?

 

You're correct. We CAN mix Coke and 7up together, but it doesn't mean that we SHOULD.

Perhaps Coke and 7up are better off serving their orignal purpose, to be enjoyed separately.

I don't think you could do any real damage to a car by mixing two waxes together, but they are specifically blended to work individually. Just keep in mind that when you mess with the mixture, you might get something that works better than you could have expected, or you could get a NEW blend that dries as hard as concrete and is almost impossible to get off the car.

I've used two different waxes, one after the other, on the same car with great results but I haven't felt experimental enough to try mixing waxes together. I have mixed compounds before to achieve a desired result but that works a little differently, and contains no waxes or silicones.

Why don't you grab your camera, and do a 1/3 x 1/3 x 1/3 hood, similar to what Presidentail does? Just tape it off in equal thirds, use wax 'a' for one section, use wax 'b' for the other, and mix them together for the remaining section. Take some good pics with a flash, halogen or direct sunlight reflection to show differences (if there are any). I dunno just a suggestion. I'm curious now. You should do it lol.