Water usually gets in when the passenger side drain under the cowl gets plugged with debris, this is a most often caused when the car is parked under trees with small leaves, the leves act as a filter and start to trap smaller particles. It is wise to check this drain often, it can be seen through the rubber comb cover where the hinge goes There is a similar drain on the drivers side and two drains in the centre of the cowl area. These other drains do not seem to cause too much trouble but should be checked so that they do in fact do their intended task.