On simply changing lanes,left to right, with vehicles behind, we got some good advice once that said one should put your left turn signals on -but that is not enough - and to extend your arm through your window and point to the lane you are going to turn into. We thought it good advice after an incident in Colima when, while towing our towed, we wanted more room to turn and go back the way we'd been travelling: we pulled into the right lane to give us more room on the fairly narrow four lane road, but when we started to turn left (having checked that the lane was empty behind us) a car suddenly screeched to a halt beside us. The lady driver behind us in the right lane had taken our signal as an indication she could pass, so she turned out and hit the gas, only to find me turning into and across, that lane. No one was hit or injured, just some bruised egos. We turned and found our Walmart destination, and in their parking lot, were warmly welcomed, into a fine parking spot. We stayed two nights(a first at a Walmart) and found Colima to be a fine area to explore.