How do you get paint in the trunk drop off areas?

Like it says, how does one get the inner parts of the trunk drop offs painted?

 

Eastwood has some products meant for spraying inside enclosed areas like frame rails, etc. They come with a spray wand.
I started using Wool Wax rust preventative, their spray gun comes with a wand for enclosed areas. WW could be an option for areas you want to protect but may already have rust. Painting over rust may not be the best choice best treatment if moisture is still getting in there.

 

I just ordered two cans of the eastwood with the sprayer, let you know how it works.

 

3M makes a product called cavity wax plus

 

I used the Eastwood internal frame coating. It works well. Pretty thin and run out was a problem. Instructions say 2 cans for std car frame. I used 4 on a convertible frame. I think it comes in epoxy green and black now. The nozzle and wand look small but work pretty well