Reddit mentions of Cb Radio K30 35 Inch Magnet Mount Antenna

I have the K30 on top of my Camry now.

It's a 35" antenna: Shorter than the Firestiks, K40, and the same-ish length as the "Lil Wil."

Even that is pushing the height, as I have to stop and take my antenna off before going into many parking garages now (I just unscrew the antenna from the mount and stash it inside the car). If you don't want to have to do that, figure out what your maximum height is going to be for the places you're likely to go, and then stay under that when choosing an antenna. You won't get as good performance as if you had a full-length antenna... but you'll probably get good enough and you've already decided you're not mounting an 8.5 foot antenna so it's moot.

You could have a slightly longer antenna if you mounted it to your trunk, than to your roof. Different people will tell you differently about whether that's going to help at all and I'm not a radio engineer so I can't help you there. With that in mind, most of the antennae suggested so far would probably work for your form factor (amazon links chosen at random, for illustrative purposes only):

• 4' firestik
  
• K30
  
• K40
  
• Lil' Wil
  
  With my 35" antenna around 7 feet in the air, powered by my 4-watt car radio, the longest I've skipped a clear conversation is ~1,348 miles (and I receive from all of the US, southern Canada, and Hawaii). I don't have a decent measure of the line-of-sight range yet as there seem to be precious few locals around where I live.
  
  I note that it looks like the Firestiks are often sold separately from their mounts, whereas the Lil' Wil and K30/40 come with everything you need (antenna, mount, coax).