[Toroi]

As for the weather system, you could use a Streamer and put areas wherever you want the weather to change and help yourself with these functions

https://sampwiki.blast.hk/wiki/SetPlayerWeather
https://sampwiki.blast.hk/wiki/SetPlayerTime

As for the second question, you can help yourself with the following functions

https://sampwiki.blast.hk/wiki/AttachObjectToVehicle
https://sampwiki.blast.hk/wiki/EditObject