Nissan doesn't mark up their cars $10-20k over. The dealerships won't get away with it.
Some will be asking that much, but the cars that are actually sold will not be sold way over MSRP. At most, $5k over if they're lucky.
Now a company like Porsche, BMW or MercBenz can easily get away with $10-20k over MSRP because they're premium luxury brands.