Deck lid help

[craigfree]

I'm having a lot of churn with the deck lid. The problem I'm having is the deck lid seems too wide at the front to sit in the channel created by the side sail. If I flex it to make the front fit, then the rear is too narrow. Does anyone have any advice?

In this image, the deck lid is approximately square to the chassis and body-overhanging evenly on both sides.
Thanks