Thanks Dave, thanks Carolyn.
Dave, cloning out the car roof is a thought that has grown on me since I posted and it wouldn't be a difficult job. Might just do that.
I know what you mean Carolyn. I'm not a train enthusiast beyond their potential for photography and that has meant a bit of a learning curve. Choosing the right platform by wind direction, recognising that photographing northbound trains in the morning means shooting into the light etc. etc. have all been hard lessons.