Tricky adding colour to a monochrome car as the only colour is the rear number plate and rear lenses.
Black wheels with yellow rims, add front fogs, heavy yellow tint on all the front clear lenses and side repeaters, dark smoke rear lenses.
That makes the yellow your seconday colour (various tones of grey being base colour) with some yellow on sight from any angle and the purple calipers will be a nice contrasting detail. Any stickers should be yellow with purple highlights/detail.
Just a thought, easy enought to Photoshop.