Been chasing this sub20 for awhile and was surprised that I got it even though the driving is pretty mediocre. After reviewing the video and data I am sure there is a 1:18 in the car. Maybe I need to let @JoeMcGuiganRacing take it for a spin.

Mods:
Brembo BM6 380mm BBK - front & rear Endless ME20
KW V5 Coilovers with Z07 spring rates
Forgeline 19x9.5 & APEX 19x12 
Nankang CR-S V2 265/35ZR19 & 325/30ZR20 (new)
Magnaflow X-Mod Cat Back Exhaust
Verus Engineering front splitter
APR Performance GTC-500 wing
GM track spec alignment & TC off