Attacking fields with GVs is quite irritating thing usually. Because of all these forests, hedrows and trees you need to get very close to field. You drive say 5 minutes, comes closer and guess what happens? BOOM! Another guy sit at field with engine off, hear you from far away ( and see you too, probably) and pick you off as soon as you get out of trees. Doh. Another 5 mins to drive for some end. And again, and again.