I used to have A Cox powered tethered car. Kinda looked like an airboat. never ran it tethered. Would haul ass in a straight line though
Had one of those myself. Never used the tether either. Start it and let it rip. Then chase it! LMAO!!
I used to fly control line aircraft as well. Only had two plastic ones though. I bought balsa wood kits and built them myself. I really got off on the WWII multi-engine stuff. Had numerous P-38s, two B-17s, culminating in a scratch built Convair B-36 Peacemaker with six Cox .051s. Wish I had kept that. Only flew it twice, handful to gat all the engines running, even with an electric starter specifically meant for those little Cox engines. Sold it to a guy who wanted it strictly as a decoration.
The F-82 Twin Mustang pictured below was a radio control kit I converted to control line. Two big old .45s for power. You should have felt the pull at the handle. It was a three-line system, so the engines could be throttled. I built it for rc originally, then converted it to cl some years later. Hence the aileron servos are still in the wing keeping the ailerons fixed. Sold it as well. Where I lived in Ca at the time, there was a club that flew control line in a large park, had their own paved circles for doing so. I sold my cl stuff before moving from CA in 2002. Just don't have the time to fiddle with such things anymore.
The third is a radio control Messerschmidt ME-323 Gigant with six electric motors. The last rc plane I ever built. Sold it as well before moving to OK.
Got into rc helicopters when I moved to OK. The one pictured was the last. Was out flying it one day, and one of the three servos that control the main rotor failed, and the dang thing nose dived straight into my Rangers windshield. Cracked it big time. What the heck do you tell the insurance company? LOL! So I paid for a new windshield out of pocket. Won't do helicopters gain. If a small one with a fiberglass rotor can crack an auto windshield, imagine what it would do if it hit you, or someone else!