Had the black serum & 2 coats exo on top professionally applied...did the inside, glass & alloys myself. cost £750 ish for my estate 3yrs ago.
exo wears off (as it will) so I top up with cv2?? the spray on wipe of stuff...black serum (BS) still solid & yes tar spots & bug will still stick...but use their tar & bug removers which are BS safe & the tar & bugs wipe off.
I use a jet wash on medium setting to clean car, then foam, then two bucket & merino wool mitt wash....car comes up shiney, & water beads off.
I use all their liquid products & have various other brand brushes (also EZ wheel brushes), MF cloths, two dedicated buckets with grit guards & scrub boards...
Basically when you clean a car the idea is to remove all dirt, bugs etc. without scratching the paintwork. The BS basically means that you do not have to then polish or put sealant on the car ever again as the paintwork is perfect...the only reason I put the cv2?? on is to top up the water repellence & thus dirt repellence...
PS I live in the Highlands & near the sea & a sandy beach....so grit, sand, salt....etc...