I am looking at used 2013 model S p85. you can get some decent ones around $80-85k. Thats a $30-40k price drop in 2 years! However, my friend was telling me the 2013 is loud inside and the 2014 is better since they sound proofed the car more. 2015 is even better. I haven't noticed the difference. All the p85 I am looking at have the 21" turbine wheels. Comments?