[Perfectlap]

Most Porsche owners never go near a track/autocross and not many do much modding so it might turn off the average the buyer who isn't sure if they'll like how a modified car rides/sounds. Aftermarket parts, in my experience, will only fetch some value if they are a well known name. Well known as in known to be expensive.

your lowering springs might be an issue in that it will be too expensive to return to stock to make it worth doing for you. Perhaps a younger type buyer might be interested in a lowered car but I think it will put off most 2nd hand Porsche buyers based on polls that seemt to indicate that the average Boxster owner is well into his 40's and not intending to autox/de.

definitely remove the plasti dip. That never photographs well.