I'd have to agree, that there are differences between carnauba and a synthetic finish. The prep work is definitely the key in order to make any finish at its best. You won't go wrong with either a synthetic or carnauba.

It will be better for you to try out both lsp's yourself in order to tell the difference between a carnauba and a synthetic, as well as which lsp you end up liking the best.

 

If protection and durability is something you desire then use Zaino.

 

I've always used Turtle Wax paste on my cars, with decent results.

The last time I waxed it was a month ago. We had our first downpour last Sunday and the water didn't even bead off of the car, it just made sheets (like a car that had never been waxed)

Do you think Turtle Wax changed the formula?

I don't expect the world from a $3 tub of wax, but it never did that to me before.

Would I have to totally claybar my car if I were to change brands of wax?

 

Only if it needs it, but if it hasn't ever been clayed then I'd do it. Changing brands of wax doesn't make a difference about the need for claying.