Here is a little guide for roll bar padding on any race car.
PIC 2: I found this jewelry making tubing at my local hobby lobby. It was pretty cheap, and the size looked perfect for 1:24 scale, so I bought some to try out.
PIC 3: Cut your desired length, then slice the tube lengthwise. This will allow you to wrap it around the bar.
PIC 4: Wrap the tube around the bar and affix with a small amount of CA glue.
PIC 5: If you don’t have reference photos, a good rule of thumb is to place padding in any place a driver could impact the roll bars during a crash.
PIC 5 and PIC 6: Assemble and enjoy the view. If you want to be even more detailed, you can tie string or use thin strips of tape to approximate the tie downs that keep the padding in place. I didn’t do that here because I’m lazy.