Tailshaft Subaru 2002 Outback wagon

[wishiknewmoreaboutcars]

Hi, new to forum. I have a Subaru Outback wagon, it's a great car but the tail shaft needs replacing. The problem began a few months ago, a shuddering in the left rear of the wagon. Mechanic said it should be okay to drive he thought it was probably a rubber cap needing replacing but now he's had a proper look says tail shaft needs replacing. He can get this part made, cost about $1000 ... also, the 4 tyres need replacing ... other problem is some leakage into the vehicle from the drains in the sunroof (passenger seat and now at rear of wagon too. I'm wondering should I put money into the car (service will be over $2000), or is this just the beginning of other problems? Is it time to let the Subaru go?