Isn't 0% interest a scam? I mean if you take a note on a car at 3%, dealer financed (to 'gain' any incentives) you aren't going to be able buy the same vehicle at the same price, off the lot. No way in hell. They build the finance charge into the sales price.
With today's interest rates you have to give up the incentives to get 0%. Up until about 2016 the auto makers were trying so hard to move units and the interest rates were so low that you could pick up the 0% AND the incentives. My wifes 2014 escape we purchased at invoice, then took all the incentives and financed it at 0%. Those days seem to be long gone...at least while we have a decent economy.
The other thing I do is prequalify for financing before I ever start looking. I go in and am honest with them and tell them that I can get X% from bank X. If they can beat it I will take their financing, otherwise I will bring a check. 9 times out of 10 they beat the prequalified financing.
I do most of my negotiating via text or email while I have the car in my possession on a BCA (borrowed car agreement). As I said earlier, it usually takes about a week, sometimes two or three.