No flexibility at all as far as I know. However, I've had very good success with GM 3rd party leads. Like all 3rd party leads you have to weed through the bad ones, but there are buyers in the mix no doubt. It's imparitive that you are the first or one of the first to contact these leads since Gm sends each lead to about five dealers. If you can get the buyers that purchase within the first month of sending the lead, and you have the follow up process in place to get the 60 day and 90 day buyers then you can have great success with these leads. I've had a tremendous ROI month to month with this program. What I find promising but troubling and the same time is that every month I look at a report from GM saying how many 3rd party leads we sold and how many leads we got that other dealers sold. Let's just say even though we've had success there is room for improvement because there are many buying from other dealers, but I know location plays a good part in that as well.
Sorry, I know you didn't ask about all that. Just my two cents, but no you can't change how many you get or the radius to my knowledge.