One helpful way to do this is to 'farm' the streuners. Before you start, fly through the map and collect as many of them as you can on you. This can make it much easier, as you get a nice little boost to start.
Another tip is to have a friend or two help you out by doing the same thing. While you are shooting they fly around and collect a few. Once you finish up with your current mob, you fly to their position and start taking them out. Maybe blast them all once to start so they stay on you, freeing you friend to start collecting them again.
My third tip is more expensive. Use x2 (or x3/x4) ammunition, which will reduce the time spent on each kill.
Oh, and make sure you are running with at least a few speed engines in your configurations while traveling. A few seconds saved or here and there really add up in the end.
I hope some of that helps you.