I just recently bought a 2012 GTR 215 and and want to do some mods that won't void the warranty. Also wanted to upgrade the exhaust and add a better intake.
Vtech tune..r is a performance remapping of the ECU.
With a 1K ceiling you're gonna need to do all the hull freebies...plus...lets see....
4" diy up front air intake...$100-$200...depending...a good used S3SC wheel and front housing...$250-$350 depending...a good used solas 14/19r...$250-$300.
Those mods will get you over 70mph...everyday. That's about as cheaply as you can get where you want to go.