The Mustang crowd around here are all ages. I see mostly the older crowd cruising in their 2005+ verts with their baseball caps and trophy wives. The younger crowd mostly drive New Edges and older.
Something else to consider is that younger folks probably won't have as much expendable income as someone older.
A young person's Mustang is more likely to be their only car, while the older folks might only take their Mustangs out on the weekend and use something more "sensible" as a daily driver. As a result, you're more likely to see that younger person driving a Mustang than an older one, even if ownership is the same.
2011 GT Premium, Auto, 401A
Kona Blue Exterior, Charcoal w/Grabber Stripe Interior.