Sorry to hear about your accident, I haven't had experience with make-up myself, However my girlfriend was also in a bad car accident which left her with scars from reconstructive surgery and I asked if she might have an answer.
She said it might sound stupid, but tan first and it will help fade your scars out some. Then concealer will be your best friend, try not to use an oil based concealer. She recently played around with make up from Estee Lauder and found that the "Ideal Light Brush on Illuminator" works like a charm.
Try to get one that's around your skin tone, also works on dark circles under the eyes. She said using a little bit of coco butter lotion everyday will help lighten up the scars as well.