Unhappy with interest rate

I'm buying a new vehicle and said to the garage that my prefered finance company is bankfin/ford credit, as I am a client of absa from 1995 and all my vehicles was financed thru bankfin or ford credit. I was supprised when wesbank came back and offer me more than one and a half persent less than bankfin on my interest rate. So I wonder how do they rate you ? <br> Regards.