Should I leave the heater box out?

Hahaha! I don't drive in the winter or rain. I have used it a few times in the evenings in the past. I do want speed, but even more it'd like to clean up under the dash. I don't think the few pounds I save will do much, but man! It looks clean and uncluttered under the dash. A few plates and some carpet, then I can fab an under dash cover.