I was a booth painter for some years. Normally we sprayed with catalyzed paints such as PPG. We also liked Sherwin Williams for non automotive applications. There is a downside to just about every kind of paint.
Spray cans like Rustoleum and most evaporative paints are limited. Some are better than others, but they just do not last very long, especially on the frame which is exposed to saltwater and brake dust. Whenever possible I spray 3 or more coats as per their suggestion.
When dry, I try to spray a clear coat sealer over the top, maybe in two coats. For some reason, sealers are extremely sensitive to dust. They wrinkle up with even the slightest surface impurities. Duplicolor is a little better than others but I found the best rattle can clear coat to be Krylon acrylic urethane. Polyurethane is better, but yellows over time. Acrylic urethanes lay down nicely and will stay crystal clear.
The best paint is catalysed or epoxy. These paints do not "dry," but "set.". Eastwood makes a 2 part epoxy spray in a can. They also have another (1 part?) epoxy spray too. They are expensive, $25.00 per can. I've used them both and found them to provide good coverage, lay in well, and set up hard. I've yet to mention them in my own posts, because these are relatively new products that have no proven track record, at least not in my world.
I've never had overspray problems. I work inside the garage but would never spray anywhere close to another car, no matter what the paint. Overspray is quite unpredictable, even in the garage. Ait currents change with the weather, humidity, and the temperatures inside and out. I've touched up the Ranger once or twice, but covered the entire truck with drop cloths first.