Hawthorn shieldbug

I was driving home when I felt something on the back of my neck. Feeling for it, I brushed this fellow off with a certain amount of distaste. When I got home, I looked in the car footwell but there was no sign of it. I went to the office, sat down and felt something on the back of my neck. It was back! I have no idea how it managed to find its way back, and no idea what attracted the thing to my neck. I got my own back by capturing its image. 
The depth of field is very shallow, but because it was lively I couldn't do a focus stack as I would have liked. If I'd thought about it I would have cooled it off in the fridge for a while, but I never know how long to do this without injuring the bug. Anyway, nice colours.