That is not normal man! The car is only 6 months old and it is already encountering those kinda of problems. i think the dealer should replace the entire car man. Just a tip when buying cars. Check each and every part of the car, especially the engine parts. Check even the smallest detail like the bolts for example. Check if there is no missing Differential Cover Bolt. Sometimes when the differential cover looses its bolts, noise builds up when stepping at the gas.