Well if the company is gone then go direct through Dynavin or one of their listed distributors. If the company is around, make them warranty it through whatever laws your country has. (ex. here we have a Small Claims Court).
before doing this make sure again it's that particular unit and not just something being installed wrong.
OE CSL WHEELS - OE CSL BRAKES - OE AUTOFOLD MIRRORS - CSL TRUNK - CSL DIFFUSER - AA SPORT TUNE - AA PULLEYS - BILSTEIN PSS9s - AS 40% SSK
CF CSL RACE LIP - NAVI - BMW PERF CF STRUT BAR - BMW GROUP N MNTS - GRUPPE M CF INTAKE - UUC SS BRAKELINES, TRANS MNTS, RTABs - 4.10 BMW M-SPORT DIFF