Look at this product from Digi0Key: https://www.digikey.com/produc.../289-1316-ND/9975963
A 16 foot strip costs about $110. A 4 inch cutting from the strip has 6 LEDs on it. It is designed to run on 24VDC.
Can this run and look good on 18VAC (after suitable rectification)? The cost-per-car economics for the strip itself is good--thinking about passenger car lighting. But maybe once we add AC to DC conversion and other necessary (protection?) circuitry, it would not be.
So that's my question: Is this product suitable for our uses? Here is the app sheet: https://www.jkllamps.com/pdfs/JKL-AS-ZFS-LED-FLEX.pdf