Hard to tell Soup, the only bit where I can see vignetting is top left but there is none top right. You were using wide open aperture so shallow DoF is to be expected and I feel it works fine here. I think it could do with an extra half stop of light, it seems a touch dark BUT i am at work right now and this monitor is very dark so it might be fine when I look at home.
not a fascinating image for anyone not into cars (like me) but good treatment of the subject so well done for getting out and taking pictures even when you couldn't find much to take
Cheers,
Rob