I have been reading and many say to do it on the ppf. I have the rexspeed and my ppf installer said they would do it after as well. They normally remove the spoiler and then wrap the truck and spoiler and reattach.
since the spoiler is attached with 3m, i would have them apply PPF and then put the spoiler back on, this reduces the chance that adhesive will get embedded into the paint and will make cleaning it easier if you ever decide to sell.
since the spoiler is attached with 3m, i would have them apply PPF and then put the spoiler back on, this reduces the chance that adhesive will get embedded into the paint and will make cleaning it easier if you ever decide to sell.