I can't count how many times I've answered this question about old Meguiar's products and I have some pretty old products dating back to the 1940's and 1950's, some probably go to the 1930's
Here's what I post about older products...
Shake the product well and if it has an uniform consistency and appearance, then it's probably perfectly fine to use.
I rubbed stains out antique lacquer paint using a glass bottle of M04 from the 1950's with no problems at all... MGH-4 Hand Cleaner - Still Good After All These Years!
Over the weekend I used a bottle of MGH-4 Hand Cleaner that is Post WWII and probably from between 1950 and 1960 to remove stains from antique lacquer paint on a 1938 Packard Model 1603
Lots of people will join our forum and ask the question, What's the shelf life of Meguiar's products?
The official answer is 3-5 years as long as the product hasn't frozen. That said, if the product has never frozen it's possible you can shake it up and if it still has a uniform appearance and consistency it's probably perfectly fine to use. Such is the case for this old glass bottle of MGH-4
Here a few pics...
A protective plastic wrap was placed on the paint to protect it while the car was transported from the East Coast to Palm Springs, California. After the plastic wrap was removed it was discovered that the paint had been mottled or stained after moisture got underneath the plastic. Photos courtesy of MeguiarsOnline.com Before Cropped out close-up from the same shot above... From the front of the roof "You never know what you can do until you try"
For this particular project, I actually took a good selection of both old and new technology
because this automobile had both antique single stage lacquer paint and modern basecoat/clearcoat panels. The doors, roof, hood cowl, and rear light components were all single stage, the main body and fenders were basecoat/clearcoat.
All of the antique products appeared to be completely fine to use and the antique can of M16 Professional Paste Wax was not only in perfect condition but this can has never been used and never even broken-in.
A few after shots, it's hard to photograph such a large car while it's in the garage...
After all the work was finished we toasted the survivorship of this classic Packard using some antique Meguiar's Mirror Glaze Glasses.