Is the bypass valve necessary for normal driving in rain, or if car goes thru car wash? Or is it more if you decide to cross a river in your car?

 

If I were you, I will just get it just in case. I would hate myself if I fuked up the engine when I had to go through a puddle of water.

 

The bypass valve is actually very useful. It filters out snow, rain, or anything that might do harm to your intake/engine. Better safe than sorry, plus it's not that much more to get the bypass valve offered by AEM.

 

Just pay the extra $40 and get it to be safe. I cut out the fog holes in my car so the filter is open to the air pretty much. I know I feel safer with the bypass valve here in San Diego where it doesn't even rain that often.

 

I would get it. The valve isn't that much more money and it is a good piece of mind.