I don't drive a Cyclone TC but I've owned other touring cars, currently a TC6 and 417, and the fiberglass tape is the most popular, it holds very well and a roll will last you a long time. Here's a link to some:
Some people use velcro straps, you can find ones made for your car or just go to the local Walmart and get some velcro in the craft secion and make your own.
The last option would be some type of brace but they tend to be heavy and if you run a different sized pack it might be a hassle changing it around, you can do a search to see if anyone makes a Cyclone specific one.
I'd just go with the tape or velcro..