I have a license, I haven't installed on my IONIQ 5 but I would consider something like this: https://www.amazon.com/Bingfu-136-174MHz-400-470MHz-Antenna-Transceiver/dp/B07TT3HBLP

That antenna is crap but I meant for you to avoid the other kind of mounting, the magnetic kind, holy shit do not get the magnetic kind, it would fuck up the IONIQ 5's paint soooooo bad. What happens is that fine metal dust collects around it over time. (prev car was a old ass beater santa fe so I didn't care)

Plus, it's just safer with an actual clamp.

(I think a decent TX might melt that stubby antenna, I really only use stubby antennas for RX-only places)