Question about a Lexus?

My customers have always been fascinated with the Lexus ISF ever since it's first release. My customers plan on buying my customers dream car when my customers is finacially ready. The thing is, my customers rarely see a Lexus ISF on the street and that gets me really curious on why MB STAR C4. Is there a reason why they are barely seen in the streets? And also, what are some pros and cons of the ISF? Your answers will greatly be appreciated.