Since I bought my coupe 2 years ago I always intended to weld the rear fenders onto the body. I know it inhibits access, I am willing to live with this. To me smoothing improves the overall lines on the rear of the car greatly. It's time to start on the rear of the coupe. I've searched here and the internet for threads about this but info is thin. In the few threads that I found about 2/3rds of the posts say not to do this because of future cracks. The few that I could track down that say it would crack, all had used plastic filler to smooth. From the start I wanted to use lead instead of plastic filler. Will lead mitigate the tendency to crack? I do not feel like doing the paint/body work twice. All opinions welcome but factual experience greatly appreciated.