I always replace both my engine air filter and cabin air filter once per year in all my vehicles. Typically it's a safe amount of time where there will be sufficient buildup and not risk any adverse effects on the vehicle. I typically buy OEM products when it comes to Lexus and Toyota, but in this case, because there are so many air filters out there I decided to compare the OEM version to a cheaper alternative. I will also show you how to easily replace both of the filters in your 2016 Lexus RX 350.

Here are links to buy the products if interested:
Generic Cabin Air Filter https://amzn.to/3oIBNAk
Generic Engine Air FIlter https://amzn.to/3uLUtTS
OEM Engine Air FIlter https://amzn.to/3sBct0z
OEM Cabin Air Filter https://amzn.to/35Z44w2