hagling is not exclusive to skylines, nor imports, nor cars in particular.
Your own method of hagling is up to you.
the use of white lie's are common place, cash offers, etc.
show that you are serious with some cash.......if you have the whole amount even better - take the price you are willing to pay for the car with you in cash. Not a cent more, then go there and tell him like it is, this is how much I have and nothing more. If he wants a sale you will get your car.