Basically for the scale look plus it gets the oily exhaust out of the cowl.From other reports the extensions make little difference in performance and it sounds great.No I'm not satisfied with the tank location the carb is lower than the tank.it sits at just above the bottom 1/4 level,however its not bad if your aware of the problem.You keep your carb closed until your ready to start and you may get a couple drips out of the carb but it seems to start and run well afterwards,I'll do a test flight first then maybe I'll modify the tank location.Today is test fight day..SteveD
nice lookin plane elmerfud goodluck