We're running an internal migration of all old players' stats to our new highly advanced statistics tracking backend. This means that stat changes will be a bit delayed while we ingest this huge backlog of data. Nothing is being lost, it'll just take a bit longer to show up in the in-game UIs.
Cars, trains, ferries, planes, smaller boats, bikes, skateboards...etc. etc
The only things I haven't been on is a submarine,( which i don't want to go on) and a helicopter.