If you only need it for occasional use and don't have to have TV quality, consider the very inexpensive USB endoscopes available on eBay and Amazon. You will find them with a variety of lengths, resolutions, and degrees of flexibility. Once plugged into your laptop or phone you configure it and use it as a webcam. The one I bought is 720p. It allowed me to inspect the inside of my Mini's LH fuel tank. I chose a highly flexible model and later found when I did need a more rigid setup all I needed to do is tape the cord and camera head to a length of coat hanger. While not perfect, at only about $15 it exceeded my expectations.