Or you can just do it this way...
1) Let the first run sell at or above MSPR (pre-ordered and allocated).
2) Wait for the larger dealers' lots to start filling with about 10 RTs and 3 SRTs (if that happens in 2008, great! - If not, wait till 2009).
3) Walk in and tell them you'll pay them 10% under the window price.
4) If they don't hit your exact number, leave and drive up the street to the next dealer (easy to do in OC, LA).
To heck with those guys...they don't REALLY care about you. You're just a number at the end of the day (literally). Give them the number YOU want.