Needswings have tested their original CAI (SRT6 version) for quite some time with no ill effects.
The SRT6 members on this forum who have the aie intake reitterate this.
At xxmph a miniscule difference in the grill will not make one iota of difference to rain ingestion. Look at the stock setup - that has two tubes to funnel the water into the engine, then pool in the air filter housing!