First off, no a "Sherman Williams" store is not for automotive, they sell house paint and industrial paint. You need to find a parts store that mixes paint, or an autobody supply store in your area, or order it online like I said. I have four jobbers near my house, one is a Parts Plus store that mixes PPG and sells all the autobody supplies, one is called AutoFinishers, they sell crash parts, and autobody supplies. You get the idea. Next you need to buy a pre-flexed primer, or a standard primer that you add the flex agent to, the same with the clear. The Transtar primer I mentioned is just a pre-packaged primer, you can use any primer or clear you want, but you have to add the correct flex agent to it. If you choose to buy online, Transtar has the primer I listed, as well as clears available. If the qt's of paint you have are already reduced you would be cutting it close to paint all that, if they are not reduced you have enough, most base coats are 1-1, or 2-1 with the correct reducer. You can't use an air brush to do that work, it will look like sh*t, automotive base coats are designed to be sprayed through a standard HVLP gun, usually a 1.4-1.5 tip, same with the clear. If your car was painted by someone you should contact them to see where they bought the supplies, you should use a clear from the same manufacture as the base coat.
