I'll resond to this only because Im a huge aerosmith fan as well.
Everyone has lower abs, you just have to get at a low enough bodyfat to see them. For the low abs, Im talking about 6 percent and lower.
You can increase the size of your abs slightly to make them appear more and strengthen them. My favorites are just simple crunches on a swiss ball, with a weight across your chest. Start with at least a 45, and work up to 2 45's..Kep them reps high and hit em hard. Train em twice a week if you can.
The best way to drop bodyfat depends on your size. If your below 15 percent BF and your currently on a good program that includes diet and a solid base of basic movements like squats, deads, rows and sprints, do a search for "Ripped City".
If your not on a solid program, get on one, then supplement it with "Ripped city" after you been on workin out for at least 3 months.
For diet info do a search on "John Berardi".
Get a Grip!