In FS9 aircraft.cfg:
[SMOKESYSTEM]
smoke.0 = -08.030, +40.300, -50.916667, Opensky_revspray
smoke.1 = -08.030, +40.300, 50.916667, Opensky_revspray
[lights]
light.0 = 3, -111.35, 0.00, 7.80, fx_navwhih
light.1 = 2, -111.35, 0.00, 7.50, fx_strobeh
light.2 = 1, 50.60, 1.50, 17.80, fx_beaconh
light.3 = 1, 50.60, -1.50, 17.80, fx_beaconh
light.4 = 1, 8.30, 0.00, -12.05, fx_beaconb
light.5 = 4, 106.00, 0.00, 4.50, fx_vclighth
light.6= 9, 10.083, -18.000, -15.403, Gear_rainwash_xl,
light.7= 9, 10.083, 18.000, -15.403, Gear_rainwash_xl,
light.8= 10, 100.500, 0, -13, Gear_rainwash_xl,
light.9= 8, -135.64, 69.5, 0, Rainwash_xl
light.10= 8, -118.59, 39.167, -7, Rainwash_xl
light.11= 8, -117.13, -39.167, -7, Rainwash_xl
light.12= 8, -136.86, -69.5, 0, Rainwash_xl
And a little in the panel:
gauge31=spray!rain_spray, 0,0,10,10 //for engines water spray
and spray.cab in gauges ...