Keep the Sentra. You live in jersey...you see what your pip laws does for your auto premiums? In any event, given the high mileage commute, a TSX isn't that great a car to get, as it is essentially a smaller, somewhat more refined Accord. And not to get into a debate, but regular works fine for the TSX.
You would want something a little bit bigger, ie TL (which is a fine car) or perhaps a G35 (also a good car, but its got the rental-car stigma) or even an ES330 (not sporty by any means, but far more comfortable on the highway.).