Use a MF towel instead of a applicator. Spray directly onto the panel (half a spray per panel) and spread with a MF towel. Dont use too much product, you will again get streaking that way. Less is more here. If any dots or streaks are left use a ONR soaked towel to remove them, then dry normaly.
Work on cool panels, in the shade or as you said in a garage. I have found OCW streaks if it is used on hot surfaces or hot weather in general. That is why I prefer Opti seal over summer and OCW over winter time.