My reception is iffy, might need a ground strap.I don't think so, maybe it would help especially if you were transmitting, anytime I used a lip mount I've never done that but do be very careful of the molding, you don't want anything digging into the molding then causing a leak into your trunk.
Then again you could just drill a hole but I understand that's not possible in a lot of cases.
With the screws in the trunk lip mount? Hammer time?Those small hex screws have a rounded pointed tip that really grinds through the pain into the bare metal by design. They are made to create a good ground. Before tightening the screws I usually give the lip mount a little tap with a hammer just to make sure it's on as tight as possible and flush against the lip of the trunk.