Those tight spaces. So you checking to see if the car is "matching numbers". What that means to someone is a subject for another thread.
You don't have a small mirror (I tend to break them

Or you can't get a light and/or camera/phone in a good location
If you can reach it and touch it you can use some your kids or grandkids Play-Doh

Well not really I've purchased my own over the years just for this purpose. For best results you need to wipe or even clean off the surface as best you can before. You don't have to use the whole jar. If you can and the Play-Doh has been used before lay the cleanest part or side against the area and work it into the surface then from one end pull it off slowly and in most cases you have a readable copy of the area. Taking pictures of your findings will require a number of attempts from different angles and likely in a location where the sun can be used to highlight the stamping using the shadows from the sun. Here is an example from one car - two attempts.
Have used this on VINs on engine blocks or heads, VINs on transmission, more difficult to read were finely stamped tags on transmissions but can be used for casting dates in those hard to see locations. Sure there are more that I'm not recalling in the moment

I've found, for me, that it works best if I buy a set of the smallest cans so that once they are dirty I can just toss them. Remember not to mix what is left from one car into another since an uneven color will make reading the results more challenging. Was for me.