I got that a few times in the beginning...
Once a guy asked me if it was a M3... I told him it was a 135i. He seemed confused. Then he asked how much do they cost... I told him around 40k. He continues to ask why not just get a 335i then.
I asked him what he drove. He told me an Altima. I said they are nice cars.... I rented one once from Enterprise, they were all out of Maximas.
I smiled and got in my car.