I have a '98 Boxster and when I got the car the rear spoiler didn't work. I actually took it apart, cleaned it up, lubed it, and got it working perfectly. After a year, it started having issues so I bought a used one that worked well for about 6 months. My guess is over time the plastic on the wires takes a set and makes it difficult for it to move through the tubes. Should I gamble and buy another used one or attempt cleaning again?
BTW, if anyone attempts disassembling it to clean it, I suggest not removing the cables from the plastic gear racks, as they are spring loaded into those pieces and very difficult to get back in once removed.