I took my 2017 Prime into the dealer for a new Hybrid Water pump and though that was the only work I had them do, on the checklist, they checked "Critical" for the Cabin Air Filter (to replace). Now, I've had the car 5.5 years, I park it indoors, and -- unlike 99.99% of everyone else, I almost NEVER use the A/C. I'm not exaggerating. I've used the A/C maybe only 5 times since buying the car. and the heat, maybe twice. Normally I just roll down the windows (I live not far from the ocean). I don't like A/C so I've only used it a handful of times EVER. Yet the dealer had it checked not as "yellow" (replace in the future) but "red" (critical to replace now). I'll be bringing my Prime into my non-dealer mechanic for a lube & such soon, and was wondering if I should spend the money to have it replaced. (1) Can anyone think why it would be so critical when I virtually NEVER use the A/C or heat? Would rolling down the windows and getting outside air into the cabin cause it to go bad so soon? (2) How long was it before you replaced your cabin air filter? And what if I don't replace it, what are the consequences? As someone who almost NEVER uses the A/C or heat, is it going to matter? PS: In doing a search on Ebay for the apparent part # (87139-58010) there are a lot of sellers that say they're selling geniune OEM Toyota parts that are "Interchangable" with the 87139-58010. For instance, the 87139-58010 is about $50 on ebay ($56 at Toyota) but there are a bunch of much cheaper (by half) "Genuine Toyota 87139-0E040, Made in the USA". Can someone confirm is the "87139-0E040" is interchangable with the "87139-58010" or no, or if something's missing? Thanks! I'm just wondering if it's the dealer trying to get more $$ or if it somehow is actually bad (and if so, if it really matters if I replace it if I hardly ever use the AC or heat). I'm not at all mechanical so I can't tell myself. Thanks!