If you have a cat, you need a carrier. It is extremely dangerous to try to carry a cat to the vet any other way. Pillow covers really don't work all that well. And a loose cat - even on a lead, will cause trouble on a bus. A loose cat in a car can cause an accident. So, for everyone's safety - including your cat's - get a carrier that is large enough to provide for your cat to stand and turn around in when full-grown. Each cat is different, so the sizes here are all different.
I'm terribly sorry, but legislation regarding taxing internet sales have caused my suppliers to stop selling all carriers. I will work to find alternatives, but please be patient.
Contact your legislators, to stop this movement, or all internet commerce may come to an abrupt halt.
I don't generally make political statements, but this affects all of us.