You're wasting money on options that aren't right for you
Think about what you're really going to use the vehicle for. If this car is going to be your day-in, day-out commuter, performance options are going to be a huge burden when you're stuck in traffic, regardless of how sexy they may seem in your window-shopping fantasies. If you're schlepping kids from muddy soccer practices to greasy pizza parties, you might want to reconsider those cloth seats. If you plan on using it for backroad jaunts or track-day fun, upgraded brakes or a track package might be legitimately worthwhile.
It's easy to say you just want one car that can do everything, but you're better served sticking with what makes sense for you and the car -- and not going overboard and wasting money on fancy features you won't use. Often times the more desirable car truly lives up to the less is more motto.
You're not taking full advantage of the car dealer
Once again, if you're ordering your new car instead of picking what's on the lot, you'll have a seemingly endless combination of options to choose from. You should feel free to take your time and treat the dealer like a Starbucks barista, because an honest and good dealer (yes, such a thing exists) wants to make sure you get precisely what you want. They'll make sure you notice that contrasting blue trim piece on the dashboard -- the kind of special distinction that sometimes makes all the difference, often at no extra cost -- much like when your barista adds a smiley face on your macchiato.