I went the PPF route and did it myself. One thing about PPF is it is cheap and you can mess up a lot without hurting your car before you get to the cost of a pro installation.
Adding PPF behind the rear wheels is the easiest place to do it yourself. Get 3M PPF from Amazon in 6 or 12 inch widths to start. If you don't like it just pull if off. Once you get the hang of it doing, straight sections are not too bad. I have done 3 cars (fronts, skirts/rockers/door sills, rear quarters and mirrors). You just have to be patient and be willing to start over.
https://www.amazon.com/3M-Scotchgard...s%2C121&sr=8-6