I really don't see why you're trying to get around the system with all the risks that it involves. You knew the status of the car when you bought it, you knew you would be classed as an inexperienced & young driver, and you knew that you got lucky by having your boss insure via his company for you. You took a huge risk on that knowing that the insurance costs would be sky-high and that's the only reason you could afford the car in the first place: Now your luck has run out, why not just suck it up and pay for insurance legally and properly like everyone else has to?
There's being able to afford a car, and being able to afford a car. I could afford to buy a 355, but no way I'd be able to afford the running costs so I don't own one, simple maths. Sorry to be getting at you here, but I know how I'd feel if someone drove into me with invalid insurance and I wouldn't exactly be a happy bunny, put it that way.