Fantastic work!
Incidentally, if anyone's interested in more complete RainFX for this circuit, copy and paste the following into ext_config.ini:
[RAIN_FX]
PUDDLES_MATERIALS = ROAD?, ext_MAIN, RDCPA, ?Viz?, ?Concrete?, d_tails_sols, ?kerb?, ?cement?, Start, gp3r_aerienne
SOAKING_MATERIALS = ROAD?, ext_MAIN, RDCPA, ?Viz?, ?Concrete?, ?murs_beton?, d_tails_sols, ?cement?, gp3r_aerienne
SMOOTH_MATERIALS = baches_pneus, ?armco?
ROUGH_MATERIALS = GRASS?, GRVL4_1GRASS, PEUPLIERS, ROAD_GRVL_HIPPO, ARBRE?, SAPIN?, LOGO_NONE
LINES_MATERIALS = PIT_GRID, GRID, ROAD_SFLINE, SECTOR_LINE, ?line?, Start
RELIEF_MATERIALS = '{ dynamic:no & !Bx? }'
STREAM_EDGE_... = -228.52, -60.6, -43.92, -230.44, -60.6, -39.16
STREAM_EDGE_... = -59.55, -60.65, -17.52, -62.47, -60.67, 4.9
STREAM_EDGE_... = 88.37, -60.86, 115.83, 83.65, -60.87, 113.77
STREAM_EDGE_... = 59.43, -60.47, 182.43, 42.95, -60.47, 172.92
STREAM_EDGE_... = 86.63, -62.77, 242.83, 85.9, -62.71, 247.92
STREAM_EDGE_... = 177.63, -66.97, 244.3, 176.99, -67.04, 249.41
STREAM_EDGE_... = 213.74, -65.49, 252.57, 211.46, -65.47, 260.3
STREAM_EDGE_... = 215.55, -65.5, 261.51, 217.88, -65.49, 253.81
STREAM_EDGE_... = 257.12, -63.4, 166.1, 262.19, -63.35, 166.12
STREAM_EDGE_... = -337.28, -60.34, -166.91, -338.04, -60.38, -171.9
STREAM_EDGE_... = -423.69, -60.59, -158.73, -423.52, -60.67, -177.73
STREAM_EDGE_... = -461.64, -60.08, -39.76, -481.31, -60.24, -41.52
STREAM_EDGE_... = -464.11, -61.07, -19.3, -469.28, -61.16, -19.51