The Mishnah (Kiddushin 1:5) differentiates between how one acquires movable and immovable property (translation follows Yachin):
נְכָסִים שֶׁיֵּשׁ לָהֶם אַחֲרָיוּת נִקְנִין בְּכֶסֶף וּבִשְׁטָר וּבַחֲזָקָה. וְשֶׁאֵין לָהֶם אַחֲרָיוּת, אֵין נִקְנִין אֶלָּא בִמְשִׁיכָה. נְכָסִים שֶׁאֵין לָהֶם אַחֲרָיוּת, נִקְנִין עִם נְכָסִים שֶׁיֵּשׁ לָהֶם אַחֲרָיוּת, בְּכֶסֶף וּבִשְׁטָר וּבַחֲזָקָה. וְזוֹקְקִין נְכָסִים שֶׁאֵין לָהֶם אַחֲרָיוּת אֶת הַנְּכָסִים שֶׁיֵּשׁ לָהֶם אַחֲרָיוּת לִשָּׁבַע עֲלֵיהֶן:
Land is acquired with money, documents, or an act of ownership; movable property is only acquired by dragging it. Movable property can be acquired with land, with money, documents, or an act of ownership, and we stand up movable property with land to swear on them.
Ignoring Dina d’Malchusa considerations, how do things like cars factor into this? They can’t be picked up by ordinary means, but they can be driven. Is a car considered movable property, then, and one can acquire a car by driving it, which would be considered like dragging it? Or is a car considered real estate, and one can acquire a car by driving it, which would be considered an act of ownership? A practical difference between these approaches is whether one can acquire a car with a document or along with land.
