2004 Nissan X-Trail recent transmission plate/linkage broke again, should i repair or let the car go :(

Take it back to the garage that " fixed " it under warranty if recent repair . If they refuse to do it any earlier tell them you need the car and are having to take elsewhere for checking and repair and will be holding them liable for any costs due to faulty workmanship or diagnosing . After spending a lot of money with them it should get a bit of priority for fixing . I dont know the full picture and what the 2 other mechanics opinions are , so hard to really judge . If you go elsewhere get a detailed report / invoice on repairs