Jetta's don't. They use a closed system. The have a reservoir that you fill and the hose runs from that to the radiator. I had a 91 Jetta that had no radiator cap, so yes some cars DO NOT have rad caps. Here is a pic. You fill it in the blue cap on the round reservoir, the the tube runs underneath to the radiator. See, there is no rad cap.
If they pressurize the whole system like that then they use the overflow tank to release excessive pressure. I may not be an actual radiator cap but it serves the same function or else you are driving around with a pressure bomb
True. But if you just see the radiator it does not have a cap and only 2 holes for the hoses. We are not talking about 1 in a car, we are talking about 1 just sitting around. So to answer the OP's question, there are car's that do not have a cap on the radiator.
Well I know that. My car doesn't have one on the radiator. But it's up by the thermostat, I just meant that they all use some form of cap for pressure release. Cars like the Jetta just vent through the reservoir cap
The engine bay is. Its too colorful. I liked it when I first did it but the colors seem a little loud after a while. I'm planning to powdercoat everything that is colored in the engine bay and my brake calipers a dark titanium metallic color whenever I get the motivation to pull everyone of those things off and do it at once. Plus I just bought some new stuff that's going to get the same treatment