Catch the turn
An A-frame at the edge of the lot catches drivers at the moment they decide to turn in. Give it one service and one price in the top two thirds, the qualifier right under the price ("most vehicles, synthetic extra"), and an arrow at the bottom pointing to the bay. Swap the insert with the season: winter tire swaps in November, detailing in April.
Inspections
The NYS inspections A-frame is blue and white by design. The official yellow station sign has a design fixed by regulation, and promotional signs must not imitate it.
Car washes
The car wash templates list the packages and prices; the charity car wash names the cause, "donations support the Ridgeline High School Band", and points the way with an arrow. Print arrows on both sides so the sign works from either direction on the road.
From the shop: On a windy lot, set the A-frame where the building breaks the wind, with its narrow edge to the gusts; a sidewalk sign catches wind like a sail.