I noticed 2 black rubber tubes (not articulated like yours) on both sides of the car in around the same location as the one pictured in your thread. I always figured it was the drains for the engine lid.
I once owned a miata and the frame filled with water causing a big sloshing sound when ever I hit the brakes or accelerated. Turns out the drain tubes from where the softop met the body were plugged with a build up of leaves and other debris. Once I cleaned it out the problem went away. Maybe you have a similar problem with your Liz.
2006 Lotus Elise - CO, Sport/Touring, Ohlins double adjustable Coilovers, Adjustable Front Sway Bar, LSD/TC, Seamless Front Clam, StarShield, Hardtop, Stebel Horn, Tripoint Supercharger-10psi, Aquamist, ForcedFed Header, Sport CAT, Larini Exaust w/F1 Tips, ACT Clutch, Fidanza Flywheel, Porterfield R4s Pads, ULTRAdisc 2 piece rotors, Hoosier R6's on SSR Comp Rims, Carbon Fiber DoorSills/CenterConsole/AC Control Surround, Fire Extinguisher, Garmin NUVI.
1997 BMW M3 - Downgraded to Winter Beater.