Slightly sideways and a 'me-rail' but I once dropped a tin of gloss paint all down myself just outside my house. It bounced, the lid flew off, I was covered head to foot in bright blue oil based paint. I couldn't go inside my home because that would have destroyed the carpet, walls, door. Ideally I needed to strip off but couldn't as public outdoors. So, I had to think what to do. I went (dripping) to the shop next door and yelled out for them to please give me some heavy duty garbage bags and some selotape. I was able to seal my whole self head to toe in bin liners, sealing the paint inside, to get into my apartment. Once inside I sat in the bath to peel my clothes and the bin liners off me and I honestly didn't get a speck of paint on anything except the bath tub.
So what I'm saying is, three or four bin liners, or pull on some waterproof rain pants and anorack (is that a word?) would have kept the car relatively free of mess.
But where did he go immediately after to clean up?