After my oil cooler hose mishap (Oil Cooler/Line Failure at speed), I have been paying close attention to any and all strange sounds. While putting the car in the garage one evening, I noticed a strange new sound.While standing right by the right rear wheel I could hear a tap-tap noise, almost like the old baseball card in the spokes sound. As I revved the engine, the tapping increased in frequency. From inside the car, I could barely make out the sound over all the other Elise sounds. Even directly behind the engine with the lid up, it was difficult to hear. But, stick your ear down by the rear wheel and it was very obvious.So, in to Criswell before my warranty is up (June 22). The verdict was the Belt Tensioner Assembly and a new belt. No more noise, and once again a nice experience with Marty in service. While poking around on Google, I found this Toyota TSB for the Belt Tensioner. So, if you hear a similar tap-tap, take it in. If you are out of warranty, try taking along the Toyota TSB, who knows, maybe it will help to get it covered.