Which to be fair, isn't altogether surprising. Some of the whining from a few on here, none on this thread incidentally, about how people expect new cars for used money and want discounts etc etc, is at times, cringe worthy. As if any of us never try to negotiate something that is already cheap, to be cheaper.It's just what we do.
The solution to it is either accept it as part of the game or, fix the price, make it clear before people travel and terminate the conversation if anyone ignores what you've made plainly clear.
I'll discount a car in the unlikely event that someone finds something I haven't seen, usually when someone is very keen to see a car and I've probably not been round it with a magnifying glass as usual because I don't want to stop a punter who must have the car ASAP. But 99% of the time the price is fixed, discussed on the phone and not revisited until it's time to write them up an invoice.
Back to the point, I can't personally see how any promotion offers will really help. If I reduce the price of the car I'll make that clear, like "£500 off, Sale on!" etc but whatever you offer, people will think there's more to be had.