Basically what you're looking for is a good, solid foundation of existing paint that is stable and still strongly bonded to the car. Many times an original factory paint job, even after decades will meet these criteria. Also, when checking the paint, be realistic and don't ignore areas just for the sake of convenience. It will cost you more in time and money later. Typically if one area of the paint is cracked or peeling, then the paint on the entire car is suspect. Maybe the rest of the car just hasn't quite reached that point of decay, but it will shortly. So if you only fix areas that look bad, you'll likely find that you wasted a paint job when the other areas start to crack or peel in a year or two. A Gloss paint is easy to clean and resists scuffs better. This is ideal for rooms that are constantly used. Most gloss paints are best recommended to use on woodworks, baseboards, kitchen and bathroom walls, doorjambs, and window casings. The downside of using gloss paints, however, is the noticeable imperfections in the wall surface.
Airless Tip: If you have somebody who can start masking off the trim, have them start on that while you convert the airless to a new color. When changing colors with an airless paint sprayer it is a good idea to have a second bucket filled half way with clean water. Place the intake hose in the clean water gently without getting the old color everywhere in the water. Take the tip out of the airless and spray all of the old paint out of the hose and back into its original paint bucket. Be careful when doing this that you recognize when the paint starts turning watery. When it does point the gun into the first bucket and spray until it looks pretty clean. It doesn't need to be perfectly clean. When it looks good, clean off the intake line in the clean bucket and get the old color off the intake line. Now place the intake line inside of your new trim paint. When all of the spraying is complete, its time to remove all masking tape and paper and start touching up your entire home. This step is pretty time consuming because this is the final stage that really makes your home look good. The more time you spend here, the better your home will look. It's funny, but many of the colors that a paint company puts in its line would never look good painted on any wall. The colors are 100% used to grab your attention when you are perusing paint displays. People are helplessly attracted to bright colors; they are much more eye-catching and far more interesting to our brains. Now that you have primed the airless, make sure that there isn't a tip in the gun of the airless and bring it over to the empty bucket. Since there is typically cleaning solution in the hose leading to the gun it is a good idea to spray that out until you see thick paint coming out. Once you have thick paint coming out you may put your tip back in. Remember that the tip will have an arrow on one side of the handle that shows which direction it must be in, in order to spray.