I had this when buying my last car - the money was ALL mine, left to me when my Mum died & I knew what I wanted etc.paying cash for the whole sale.
I went in to one dealershop & he started talking to my husband, who pointed out it will be my car, so he should talk to me (which he mostly did) and when it came to discussing the money, he started trying to talk with my Husband again! He pointed out again that it was my car, but the salesman laughed and sad "but I bet he's paying, right?"
I got up, called the kids (who were drooling over an Audi) and said "right - we're off - I'll go to Chelmsford instead" and walked off.
The salesman called my husband back, who pointed out AGAIN, that it was my cash and my car, he was only there to supervise the kids whilst I took the test drive & signed the paperwork.
Went to the Chelmsford Dealership who got it straight away, spoke to and discussed everything with me, called me for any clarification and gave me a huge bunch of flowers when my car came in - guess where I'll go for my next car!!