Kia Xceed - Permanent shuttering noise

My Kia Xceed from the year 20something (cant remember the exact model, will update later) makes a permanent shuttering noise, similar to the noise when you have your windows partway down at high speed. This noise happens at any speed though, and it's tied to the speed im going (slow thud-thud-thud when going slowly, thudthudthud (almost a tone) when going faster). Doesnt seem to be related to the engine nor the AC. Anyone know what might be going on?