If the vehicle is trespassing and you are inside it then you are trespassing.
no they can not
have it towed away. as long as you have the private property owners permission.
Unlicensed drivers cannot operate a vehicle on private property. The insurance for the vehicle will not allow unlicensed drivers. Most states require every vehicle in operation to be insured.
If you are in Philadelphia PA Department of License and Inspections can give you a ticket on your vehicle on private property if it is not legal or there are to many vehicles on your property.
In the UK it can, if the driveway is private property.
I would not go on private property to get your vehicle without the police being present. You may end up in a conundrum. Contact the local police and explain the situation.
Call the police
If the vehicle is parked on a public street, you need a tag. If it is on private property you don't.
If the vehicle is illegally parked the police do not need your permission to tow it. The owner of private property can request a vehicle be towed if the vehicle is not authorized to park on the private property. There are other reasons in various jurisdictions for which a vehicle may be legally towed without notice to the owner.
You cannot be fined or issued a citation for having expired tags on a vehicle which is on private property. However when the vehicle is on a public roadway you can be issued a citation.
Technically, yes - you're supposed to be licensed to even be in actual physical control of the vehicle. However, this is not enforceable on private property.