I've got a 17-incher on Bridget and it's great but you gotta kind of slide around and under it. Not sure I could work with one that big on the Spyder.
Here's the common interior diagram from (I guess?) the original 550 owner's manual, next to my car. Switch gear is even pretty close. I've got 8 (lower) as pre-oil/Accusump and 8 (upper) as wipers (which are not installed), and 12 pops the hood latch instead of the oil cooler grill slats as original.