Does a buyer have more leverage buying a used car when paying all cash versus securing a loan from the dealer/owner
Yes AND no. The dealership makes money on the finance of a vehicle when done through there finance department. Sometimes they make more money on the financing then on the vehicle itself. If the salesman asks tell them you have good credit. Try to leave it at that.
It really depends on the dealer, I have paid cash for the past 3 cars I have bought, on the first one the dealer said cash is king, after a little haggling I got it for 2 grand less than asking price, he had just took it in on trade and it had not gone through his shop but that didn't bother me, the other 2 rigs I bought I didn't do as good but still got him to sell them to me for 500 bucks off the listed price. So you just have to kinda feel them out, just remember you can make and offer and see what they say, they really might want to deal. You can always walk away.