The short version: offer three tiers, make the middle one the obvious choice, name them by what the driver gets, keep one easy add-on for the upsell, and show the club price next to every tier.
Three tiers, one clear winner
Five tiers make drivers read; three let them decide. Put the tier you want to sell in the middle, make it look like the sensible choice, and give the top tier one clearly premium extra.
Name tiers by benefit
“Ultimate shine with ceramic protection” sells better than “Package 3”. Short names on the POS button, benefit names on the board.
The add-on you always offer
Keep one add-on outside the packages — tire shine, interior wipe, air freshener — so the attendant has one simple question: “Tire shine today?” Track the add-on rate by attendant.
The club next to every tier
Drivers compare. Next to “Deluxe — single wash” print “Deluxe club — unlimited, per month”. The comparison does the selling.
Seasonal specials
Pollen, bugs, monsoon mud, salt or desert dust: add a seasonal add-on for the weeks it matters and switch it off afterwards. The reports tell you whether it earned its place.
Price changes without drama
Change prices on a quiet day, update the board, the POS and the online store at the same time, and tell members first if club prices change.
Where GetCarWashPOS fits
Packages are products with add-ons (modifiers) and per-site price groups; the online store and the pay station show the same prices. See wash packages and build your wash menu.