I bought my car a few months ago (first ever car, I have no idea about these things) the tax just ran out and I went to renew it online and its saying the vehicle details aren't valid. I have the green bit of the v5, but I don't think the last owner sent off the yellow bit... I'm not really sure what to do, I need my car to get to work and by the looks of it it takes up 4-6 weeks to get a new v5. I've tried to get in contact with the guy I bought it from but no luck. Does anyone know what I can do?