The way to really get that "showroom look" is to apply a thick coat of a water based gel sealer... Like
http://www.detailingsupplies.net/Aut..._p/tvd_107.htm
Goes on with a sponge and ends up having a "DRY" finish when left on overnight....Let it suck in and apply a second coat a few hours later...
$25.00 for a gallon is a steal based on others I've seen...
Or the Adams product mentioned above seems to be very similar and should also give excellent results.
Because I wash quite often, I usually apply the cheapest "on sale" oil based products and I use the good stuff every once and a while.
If you really want that unbelievable shine, apply a second coat the next day and let dry.....
WHooooo!
P.S. Never spray dressing directly on your tires...Put the nozzle in a sponge and load the sponge up and apply in a circular motion around the tire. Roll the tires a half turn and finish the spot you missed.
Make sure you cover the first tread so you con't look like an amateur....................................