How long can you store waxes and cleaners after they have been opened?

 

You can typically expect Meguiar's surface care formulations to retain their full effectiveness for three to five years, as long as the container has been sealed tightly, and has not been frozen.

Always shake Meguiar's liquid products well before using, especially if they have been sitting for an extended period of time.


Google wax+shelf+life

 

I don't think that there's any one 'right' answer for any one product as individual environmental conditions will dictate the shelf life of nearly any product; be it a car care formulation or a box of cereal... simply put, individual products have individual shelf life constraints which are unique at each individual point within the world.

In short, if you start using a product and find that it's not performing up to par or as you had remembered it plus, it's a few years old, it's safe to pitch it and go out and buy another bottle/can.

I think the only smart thing to use here is common sense.

RP