I suspect disassembly takes the same amount of time it takes to craft the said item. At least for geiger counter this is true. I know this because I recently grinded my electronics skill up to next level by crafting and disassembling a few geiger counters. (35mins per operation)
For vehicles, I don’t know for sure. Could it depend on the mechanics level required for the part installation? Also things like character’s mechanics skill, certain attributes, focus and tiredness levels COULD be factors. So there might not be a simple answer. But the time required is not visible anywhere, that’s for sure.
For me installation/removal of level 6 components (tested ‘upgraded solar panel’ and ‘military composite armor’) at mechanics 7 takes ~30 minutes. Headlights take ~7 minutes.