Hello I Need Help With RT Decisions!?

Hi this is the first post I have put on this site, I am going to be buying a Dodge Challenger in the next couple months and was wondering whats the best way to do it? I will be buying the car with cash and am looking to get a black RT with a sunroof and Manual transmission.

My desired budget is $25000 & want to stay to that as close as possible.

1.Now whats the best year to buy the 2009-2015 I almost see no differences in appearance's so looks can be deceiving, so which year should I get?

2.Where should I purchase the car from, Autotrader, Craigslist or Ebay? I want the best deal for my buck.

3.What should I know about the RT before buying it?

Thank you & I appreciate your time!