The short form used for Switzerland is CH. It keeps everyone happy if you could use it
On to your specific question. For a stay of 9 months I really think you should rent from one of the two low cost agencies in Lausanne. You can surely negotiate the number of km you need as well.
Since you wife is Swiss (French speaking?) you could try to talk your way into having a macaron (free parking in a blue zone where you live) since you will have the same car for the full 9 months.
If the Lausanne parking authorities will not give you a macaron, you can surely find a parking spot in the neighbourhood. Just put up some posters by the buildings in the area.
I think that your total cost of ownership (and hassle) would be lower with a rental.
Depending on the car you rent/buy you can get bike racks and magnetic ski holders from the dealer or from Migros do-it, Jumbo and Coop Brico as well as some on-line dealers.
If you would like the names of the two agencies, let me know.