We will be coming back thru in about 3 weeks so maybe we will try it then.
On the subject of places to eat, in Salt Lake area there are several Chuck-A-Rama buffets. These are a notch above the usual (two above Hometown). There is one near the south end of the Salt Lake Valley that is right off I-15.
If you have never been to one, make sure to stop at In-N-Out Burger. This is the best fast-food burger in the world -- all they do is burgers, fries and drinks. Not the $10 gourmet burger, this is a good $2 burger, made fresh. The french fries get to the store as potatoes, they slice them right there as they are about to go into the fryer. There is an In-N-Out at the same offramp as the Chuck-A-Rama.
While you are in SLC, I also recommend that you take the (free) tours at Temple Square. If you are there on a Thursday evening or Sunday morning, you can see a (free) concert by the Mormon Tabernacle Choir. There is a museum, the Family History Library (want to find out who your ancestors were?), free films (I suggest that you see "The Testaments," and there is one on the building of the Temple called "Mountain of the Lord"), and it's one of the most pleasant places on the planet.
If you go to "This is the Place," or the Zoo DO NOT go PAST it with your coach. Emigration Canyon gets narrow and windy.
If you are interested in history, you also want to stop and take the tour at Cove Fort (I'm assuming that you are going down I-15 to I-70 to US 89, which is the best way).
If you like airplanes, DO NOT miss the Hill Aerospace Museum -- it's 15 miles north of SLC, at Hill AFB, but it's a must-see. There is also a railroad museum in Ogden.
If you are seriously interested in railroad history, go to the Golden Spike National Monument. On the way, stop at the Big Fill. A mile or so from where you make the turn to get to Golden Spike, there is an outdoor missile museum at Thiokol.
If you go I-84 (I agree with the recommendation) you will be going through Ogden, and will go right past the Hill museum (plenty of coach parking) and the train museum is only a couple of miles out of the way.
I lived in SLC for a while, and enjoyed it.