My cans that came with the car have an expiry date of 2005 so thought might be best to replace them ….. but to do so with the same is very expensive having to be imported from America.

Fix-a-Flat aerosol tire inflators are the easiest and quickest way to repair a flat tire in an emergency. Fix-a-Flat is designed to seal small tire punctures in seconds and provide enough inflation to lift the rim off the ground.
Fix-a-Flat seals 33% larger punctures than other tire repair aerosols and has been trusted for 50 years as an easy-to-use, better alternative to the spare tire. With its eco-friendly formula, Fix-a-Flat is safe for the user, the tire and the environment.
Fix-a-Flat has a new look! The plastic cap has been tossed and replaced with a modern Performance Top, making Fix-a-Flat even more eco-friendly and easier to use.
For full spec …… https://www.fixaflat.com/products/fix-a-flat-20-oz-emergency-flat-tire-repair
To buy a couple of these cans would cost nearly £70 having to come from America so I replaced them with a couple of equivalent “large tyre” cans from the UK at around £13 delivered.