Hello,
I just bought a 2020 CX 5 GT after having a 2016.5. I am shocked at the ridiculous size of the key fob on the 2020. It is like carrying around a flip phone. I was hoping a key fob from a 2019 will work with the 2020. If so I will order one and have it programmed. The older fobs feel far more sturdy and well made.

So far liking the 2020, first Grand Touring, last 2 CX 5s were touring. The seats in this new one leave a bit to be desired but maybe they need breaking in. I joked with the salesman about how Mazda is always so far behind in their infotainment stuff. He said I get carplay and android auto where other brands make you upgrade...I said that is great but it still will take 4 minutes for the system to start. He finally had to admit it seriously needed updating. Overall though...I am buying it for the amazing mechanical quality so I overlook the little stuff.

 

Doubt it would the 2020 has a lot more features that the remote works in most cases and usually Mazda makes them to where you can’t use one from a different series or year so I would say no as a mechanic I haven’t dealt with anything like that for sure so I don’t know but I don’t think it would and the computer in the 2020 is much more advance than the 2019 ones

 

I don’t know the answer, however, it might be worth a try. It is not related to a generation change. They made the change for all models so they may have made it interchangeable instead of making upgrades to the entire line.

That said, you may like the key if you give it a try. I have 2 cars with the old key and one with the new. I feel like I don’t have a key in my pocket with the new key in comparison. The thinner shape is much better.

Another advantage is the buttons on the side. I have fewer false activations where the car starts beeping when I am playing with the dog. Worse yet, the trunk open when I go to the car in the morning. Neither happened that often but it has not happened since I got my 2019 Mazda3 with the new key.