Thats not true is it? You've already told us the facts:
a) You owe somebody £2k which you feel you must be able to repay as part of the deal
b) You have zero cash deposit
c) You have only the value of an 8 year old Corolla as a deposit
d) You want to take out finance so that you get cashback to pay your Dad
e) You want to buy an £8k+ car from a main dealer
f) You feel you wont be in negative equity
I don't know what gives you the impression he has 'no idea of the facts', you've laid the facts out for him in this thread!
The facts are that a+b+c+d+e <> f