I think you could change the oil a little less often to balance it out some (though the VQ does like it's oil), but where you are I'd think you need winter tires (and possibly wheels).
I get about 17 mpg with mostly city driving so yo may pay a little more there.
Coming from an expensive sports car, I think the only unexpected cost is the cost of mods (hood struts, K&N drop-ins, next HFC/Y-pipe or new exhaust, LED kit, backup camera kit, etc.) Not that they aren't reasonable - they are too reasonable so seems affordable to do a lot more
