Maybe this will help.
#3Machine Glaze
The ultimate machine-applied shine. Meguiar's Machine Glaze lets you achieve a deep, rich gloss unmatched by any other polish, glaze, wax or sealant. Rich nutrients penetrate and revitalize all paint finishes, as well as fiberglass and plastic. Buffing residue wipes off easily to reveal the original brilliance and clarity of your finish. For use with a rotary buffer only Made For Professionals
#7 Show Car Glaze
Legendary on the show car circuit. For those of you who love a hand-rubbed finish, this superb glaze is guaranteed to give you that deep, wet shine prized among car collectors. This polish will outshine all other hand-applied polishes, glazes, waxes or sealants. It won't dry white, and it's safe and effective on all paint finishes. Used as part of your 5-Step Surface Care Cycle, Show Car Glaze is just one of many Secrets of the Pros that add up to a superlative appearance for your treasured automobile. For use by hand, orbital buffer or dual action polisher. Made For Professionals
From that I would say yes the main differance is #3 is for rotary's only
