This doesn't answer your question, but you may be surprised where you can lug a folded Brompton to. I've lugged my Brompton to business meetings, buses, cars, trains, cheap restaurants (went under the table), fancy restaurants ("coat checked" it) and all sorts of supermarkets, shops and stores big and small. I don't remember being declined and in fact, most people are quite fascinated by it. I believe the trick is to have it folded in the first place and the small folded size isn't very intimidating. You can also try the cheap cover to camouflage it, but I have not found that necessary at all.