Don't do it.

I've spent about two years of my life living rough or living out of a car or van.

It's crap, and it really doesn't save you anything over a cheap room somewhere, where your chances of ending up mugged/*****/dead/arrested are significantly lower. Looking back, I was an idiot. Hell, still am an idiot, but an idiot with a roof over his head.

If you must, give it a try while you still have tenancy someplace. After two days you'll realise just how crap a decision it would have been. Unless you're also an idiot.