For body upgrades look in each section under the main "wing" upgrades. Although have not seen roof rally lights like in fh1 rally add on. Just basic bumper and flare stuff.... also go to designs and find new designs and. you can choose from many liveries
There also seems to be a glitch that when you upgrade a hardware part over a dl livery, it does not update on the car visually . You need to erase the livery and reselect it, it seems
Dang. So lights aren't in there? That is odd. I can't believe the game shipped without rally upgrades again.
I wound like to create Ken Block's Ford Feista. There is a livery available to download that is perfect but the car body itself is just basic stock.
And... Is there a way to modify a downloaded livery? I created my own license plate that I put on all my cars but I'm not brave enough to select "yes" when it asks me if I want to delete the downloaded livery to add another layer.