I do have the exact same problem.. yesterday it was around 25c, i went for a 20 min ride in 5 gear, and red lignt came on, it didnt look like it was that hot, no smell or nothing, let it cooled,, checked prestone it is fine, check oil level, was fine. Had same issue last year, brought it to dealer, same darn problem this year. I bought a honda for piece of mind, well, it isn't that good. I'm not happy camper. my radiator is clean, all fluids are new. WTF. I do have a vented added front bumper. that's it. If anyone can help, tks.