a popping rattle sound coming from the front end

Im beginng to think I made a big mistake buying this car...around 12000 miles more or less i start hearing a popping rattle noise coming from the front end...I take finally take it to the dealer at 15000 miles. They do absolutely nothing, say they tightened a few things but nothing changed...anyway they try to blame it on a shopping cart dent..."Bob Hart Cheverolet in Vinita Oklahoma"....anyway I figured i wasnt going to get any help there so i did research and thought I figured the problem out "sway bar linage" so I changed them out myself and nope not the problem...however it does seem to handle tighter...anyway now im sure the rest of my 20,000 mile bumber to bumber is now void and I have no clue whats wrong with it...does anyone have any idea's what it could be I have heard alot of what people have done who had the same problem but no one has wrote they found the fix..I might add most people who have described the same problem im having owned the 2012 model...mine is a 2015 but from what i have read of the problems mine is the same.