......AMD makes a replacement filler panel between the trunklid and rear glass. If that is the case, buy it and glue it in with SEM panel bond. STRONGER than spotwelds!!! Just clamp it on with visegrips and let it dry.
I took welding classes at the local community college, and was allowed to work on personal projects as the class went along...even after the class ended. They had lots of nice equipment, great instructor who helped me along when i was over my head.