From what I've gathered from other members is that you could take delivery, drive all the way home, and find out that there's something wrong with your car.
This thread could help to keep you from returning to the dealer because you and/or the salesperson had missed something.
To start, this works best if the car you're test driving is the smart you plan on buying.
What you'll need:
A Compact Disc (music)
A music player and a AUX line
Anything that you might want in the car to test (capacities, could the dog fit, etc.)
Before you get in:
1. walk around the smart and look at it up close, you're looking for imperfections with the outside of the car. Such as but not limited to: scatches and dents in the Tridion Cell, missing/broken body parts/panels, paint imperfections. Also look for chips on the body from previous test drives (if it's an Orphan). Are the tires inflated?
Passion coupes - Check the panorama roof along the line where it meets the Tridion Cell. If it appears uneven in an area or more than one, it may have lifted. You could press your fingers on the corners just a bit and if the roof travels a bit before hitting an object, it may have lifted.
Additionally you want to check the roof for scratches, crazing, cracks, and if it is curved inward (like it has been sat on)
Passion cabriolets - Check the soft top for imperfections such as tears or discoloring. Make sure the mini wind deflector is on the top of the windshield.
As you enter the car:
2. Look for imperfections in the interior such as cracked leather seats, wet carpet (leak?), torn or discolored fabrics, appearance of interior items, etc:
Passion coupes - Once again check your roof, but this time you may want to look for just scratches, crazing, and cracks.
Passion cabriolets - Check the soft top again for water ingress, discoloring of fabric, tears, etc. Additionally you want to check where the top meets the Tridion Cell bars and windshield and look for signs of water ingress and/or if it's closed properly.
Before you leave on the test drive:
3. Honk the horn (it may not work, might happen!)
While on the test drive:
4. Request to go on both high speed roads and low speed roads if possible
5. For the first few minutes you really want to feel the car; how responsive it is, acceleration, ride quality, etc.
6. Throughout the drive you want to listen to how the car sounds. Are there any rattles, clanks, bumps or shakes? Does the engine sound like it's in normal operation? (no stalling, abnormal noises)
Passion coupes - Even when the windows are closed does it sound like one of them is cracked a bit? If does sound so the roof my be lifting.
Passion cabriolets - Does it sound like wind's getting in from somewhere around the roof? It could be not be correctly closed.
7. Test the A/C, it should work pretty well (small car)
When you arrive at the dealer:
7. Test the car's gadgets (wipers, lights, heater)
8. Test the radio out. Does the C/D player work? Does the AUX jack work? Are all speakers working properly? Be sure to see if the AM works as some report a weak AM signal in their smart.
This could help you from returing to the dealer for a fix that could otherwise be fixed on site that day.
P.S. Could this be a sticky in the newbie section?