Listening to speakers in a constructed sound display unit versus listening to the same speakers in your vehicle will not yield the same results.
You have deflections, cancellations, interior conflicts, absorption, etc. to deal with in a car environment that you may not experience in a controlled sound room. I'm sure the speakers you were listening to where closer to ear level as well. Were they on axis? More than likely the speakers were installed in enclosures as well.
The same situation applies to consumers that listen to home audio in a controlled listening room and love what they here until they bring the same package home and realize it doesn't sound the same in their home. It's a matter of fact.
Your head unit is not putting out 45 watts R.M.S. If you're looking for that kind of power output, get yourself an amplifier. You won't be disappointed.
