I did exactly what you're talking about, last year. I took the end of the original 'air horn', cut it off at the flare and attached it [the flare] to some "autozone" flex pipe and screwed it down at an orifice on my bumper, so the air rams straight in and up to my K&N. At the air box, I left the remains of the rubber boot and attached a correct size 'pvc' plumbing elbow [from any hardware store] on the upper end of the flex pipe. It works great. Water? The air flow isn't strong enough to pull droplets straight up, let alone it would catch on the ribbing if it could. It would take a very special drop of water to negotiate the two curves. Misty air might make it, but you'd have that with or without the low ram pick-up. The whole thing, including the K&N, was under $60.00. Hope this helps.
'95, white convertable, auto trans
, under drive pulley, cai, 3:73 gear. Just enough snap for a 62 year old kid! (my wife's a blond so the top MUST be down, or she won't get in!!)