This is the guard rail, catch fence, and lighting solution I came up with for Carrera slot car track. There is no existing solution available that works with flat and banked pieces of track and what is available for flat track is kind of crappy so I made my own and wanted to share it with everyone.
For details on all of the materials I used, checkout the description section of the "New Track Lighting, Guard Rail, and Catch Fence for Carrera Slot Car Track" video on my "Garage Maker Guy" YouTube channel.

Notes:
1.) All of the parts are printed without rafts or supports with 100% infill EXCEPT the "support block".

2.) The "Support Block" is printed with a dual process which prints the first 8mm at 100% infill (this is includes the section with the locking tab that locks into the track) and the rest is printed at 20% infill)

3.) The "Support Block" requires supports when printing to properly print the locking tab.

4.) Orientation of the parts is very important - see the pics of the real parts being printed for reference.

5.) I use Prusament PETG printed at 250c (hotend) and 80c (heated bed) with an enclosure that is temperature controlled at 85 degrees Fahrenheit

6.) Layer thickness is .150 to .200 (I use .200 and then use an automotive primer spray paint or .150 and print with the "Urban Grey" color to skip the painting)

7.) The "Support Block" requires some 'post-processing' to remove the support material and you'll want to bevel the edges on the portion that inserts into the track as I designed these to have very little slack and there are differences in Carrera's track (some are loose and some are not).

Additional:
Be aware that not all filaments are created equal. This is important when working with tight tolerances (especially the inside diameter of the support block for the 1/4" aluminum tubing). Print one piece and verify fitment before making multiple pieces.

Update 30 January 2021:
I've been creating and uploading some tutorial videos for the lights. These may be helpful.
They are available on YouTube here:
https://youtube.com/playlist?list=PLkstNejhzDNRDiKkudwB3dd6qpuWMk4W5

Cheers,
Jeff (Garage Maker Guy)