If the allen-key slots have stripped, then that is due to the use of improper sized / totally worn allen-key by the TASS themself. It didn't get stripped on it's own. Allen key slots are hard to strip if used properly. Let them know this ( if this dealer has serviced your car throughout it's life). This might be a good time to go for the GC upgrade kit, if you want and give the Linea a mid-life refresh.