Don't risk your money on a reweld. Why? First of all, chip tuning bmw x7 30d or Stage 1 bmw x7 G07 + iXsound is much more logical. You get a bassy exhaust BMW X7 G07, which can be “turned off” when not needed. And “rewelded” muffler is not so easy to return to stock, and resale is more difficult.