It may happen that you accidentally clicked on something, causing the vehicle to go into a filter.
No vehicle of interest
For example, when you click the eye on a vehicle, it is automatically added to a filter. So the vehicle has not disappeared, but can be found in another place.
To find the vehicle again, look at "my CarCollect" at the bottom of the filter menu, to the left of the buy/sell offer. Here you can find filters for vehicles you have bid on, purchased or excluded.
Do you want the vehicle back in the general overview? Just click on the eye again and it will be there again.
All vehicle files older than 2 years can be found in the archive. In this archive you can filter in the same way as in the buy/sell offer.