Great idea!
Useful for car creators to test different shader settings.
How to add puddles:
Save these lines into [Your install folder...] assettocorsa\extension\config\tracks\loaded\theshortesttrack.ini file :
[RAIN_FX]
PUDDLES_MATERIALS = road
SOAKING_MATERIALS =
SMOOTH_MATERIALS = garage,concrete,bo_paint_emergency
ROUGH_MATERIALS = 4WALL
LINES_MATERIALS =
RELIEF_MATERIALS =
Thanks!