switchy

Hi, My mechanic that I have used for over 12yrs has replaced my sump gasket twice due to a leak. The 2nd time was a warranty job after the first still leaked. I only drive it on weekends and start during the week. Again after a few weeks the leak has come back. I have taken it back and he looked at it and says it is weeping on the seam where the casting of the sump joins in the middle at the back. He said it is dry above the sump and this can happen and was common in the early Commodores also. Has anyone else had or heard of this issue. It is a very tidy car and in good condition. Just this leak is frustrating the hell out of me.

Hi It appears that the spoiler pillar seals are no longer working as I am getting water running out of the inside bottom channel when opening the boot lid. I say this after getting the clear coat (full respray) repaired last year. They seperated the spoiler from the boot lid to do the respray. I have been googling trying to find where I can get new seals but with no luck. I was wondering if anyone knew where I could order some from. I'm trying to avoid silastic if possible. If I must use silastic what do people recommend? Thanks