I do indeed. My car has the 34-litre tank, so I carry 2-stroke oil in 200ml plastic bottles that I bought from an eBay seller many, many years ago. I have ten of the bottles, and usually keep 5 of them in the car at a time. These are cycled with the other 5 in my workshop.Tom do you use some kind of measure and decant the oil into that and carry it around with you?
For the 42-litre tank, 250ml bottles would be appropriate.