Sorry, have to "spam" this also here for everyone to see, so I tried using T.A.R. on my car with now rough sides thanks to "salt" (or whatever it is in Finland). Result was excellent!
Did this as a test between 2 products:
Washed both front doors with ONR (new formula) using the Big Red Sponge and dryed the panels.
Sprayed T.A.R. on one of the doors and Power Clean (1:3) on the other door (not at the same time).
Let dwell for 2 minutes and agitated gently with a microfiber towel (separate towels for each product). The T.A.R. towel was much dirtier than the Opti Clean.
Washed again (2 times) with ONR and the Big Red Sponge and dryed the panel.
Did only one test-side at a time e.g. one product at a time, after each other.
The Opti Clean side still felt rough but the T.A.R. side was smooth like a babys bottom! Added Opti-Clean on top.
Question: Could there be a danger with the T.A.R. or Opti Clean if one couldn't get everything cleaned off using BRS and ONR? Did wash inside the doors also with just ONR.
@Ron@Optimum Same thing written also in this other thread, sorry, too happy!