I've been loving this circuit -- many thanks for bringing it to us. Incidentally, for anyone who's interested, here are some RainFX parameters you can use for it (put the text below in a file named "ext_config.ini" and drop that into a subfolder called "extension" within the track folder):
[RAIN_FX]
PUDDLES_MATERIALS = Tarmac?, Concrete?, Rumble?
SOAKING_MATERIALS = Tarmac?, Concrete?, Rumble?, Cement?, Contrete?
ROUGH_MATERIALS = Background
LINES_MATERIALS = Line?
STREAM_EDGE_... = -22.77, 2.54, -73.9, -4.2, 2.43, -88.07
STREAM_EDGE_... = -9.7, 2.49, -95.38, -28.34, 2.44, -80.95
[TRACK_OCCLUDER_BOX_0]
POINT_0 = -22.77, 2.54, -73.9
POINT_1 = -4.2, 2.43, -88.07
POINT_2 = -9.7, 2.49, -95.38
POINT_3 = -28.34, 2.44, -80.95