I thought it was the Ambassador too because it seems to be on the street in local traffic, not on the set of TM. Can't think of a reason why he would be driving it on the street, unless he bought it, lol.
He's looking very relaxed and tanned after his holiday. I am wondering if they are going to have Patrick keep his facial scruff for this season. We shall soon know I think.
Like the staircase it was an optical illusion (of many squares/rectangles-bldg shapes and window shapes plus the aforementioned staircase shape) and harks back to Hitchcock's Vertigo - a clue perhaps?