You want to pull a nice cold charge of air because it is more dense. If you have an intake that pulls directly from the engine bay the air will be hot. Take a look at where your stock intakes pull air from on your car. You will notice that the air is being pulled from the wheel well area, not directly from the engine bay.
I haven't really looked at the K&N intake so I'm not sure where that kit pulls air. The Z1 cold air intake just came out and there is a Black Friday/Cyber Monday special running. The plumbing for the CAI puts the filters out in front of the car so you get a nice cold charge.
As for heat soak issues... you know plastic heat soaks too. You are kinda screwed either way.
https://www.z1motorsports.com/air-in...bf-p-8935.html