Your Lesser Harmonica Is Riding Shotgun
I suggest you try different brands of harmonica. You will identify a favorite. Along the way, you will build up a small stable of rejects. What should you do with those harps? Take them for a ride.
While these harps play for your junior varsity, that doesn't mean they have zero value. Send your also-ran brands out to the car. You won't worry about excessive heat/cold because you have little love for these harps.
Tuck a couple of different keys into the console and play a lick during your red light waits. Big Warning: Do not play while actually driving. This is strictly a down time activity.