Driving A "Boat" In The Rain

My medium sized car is at my mother's house because I drove her up to my place in her car. She has a Mercury Marquis. I needed to take her to the doctor and also to go to the pharmacy to pick up her meds. I drove to the store today in a heavy rain. Driving her car was so foreign to me that it might as well have been a boat. I'm not use to driving a car which is longer than my own. The car is very comfortable. It is luxurious. I'm just not sure where it ends when I pull out of a parking space or am turning left with traffic approaching in the near distance. It also makes me nervous because it's not my car. How terrible I would feel if someone hit it or dinged it in a parking lot. Can't wait to get back into my Cougar even if it is less of a luxury than the Marquis.