I honestly prefer salespeople who I work with to have expensive cars/clothes/watches. Why? They are servicing their clients correctly, recommending the right stuff, and growing their business just like I want to grow mine. A salesman in a Camry looks like he hasn't grown up since being at University. A salesman in an S550 AMG to me looks like a salesman that has earned commissions over and over again on accounts and so I can trust his advice AND he will want to get me to grow so he can move up to the S600
What this says is - don't worry about looking "too good" at what you do or looking like you make "too much" money. We're here to succeed not be average.