First, isolate which wheel area.
Roll down all windows and drive slowly down a nice quiet residential street with lots of trees. That should make it easier.

If you hear a thump thump, it seems there might be something like a screw or a nail in the tire. Maybe the thumping item was against the pavement on the bottom of the tire when you checked?

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85' 300D No inspection, No registration fees, Cheap insurance
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