1. Panel gaps
The smaller the gap between panels, the better the design and manufacturing process. It is HARD to make bodies where the panels fit together tightly.
2. Driveline lash
Put your foot on the gas hard then take it off - if there is ANY “clunking” or mechanical noise, that’s poor design and quality of bushings and other mating components in the driveline
3. Mirror paint
Get close and look down the side of the car - is the paint still mirror smooth? If there are any ripples at all, this means they’re not spending money to smooth out the body panels adequately before applying the paint.
4. Switchgear
Is there a slight resistance and smooth clicking feel to the switchgear? It is easy to use cheap components here. The absolute master at this is BMW - go turn a light switch in a BMW and you’ll see what I mean.
5. Engine smoothness
Open the hood and stand a glass of water on top of the engine. Start the engine. Did the water spill? Now rev the engine hard - did the water churn in the glass much? This is a sign of how much work went into balancing the engine components. BMW, Lexus and Toyota do well in this test.
6. Transmission shifting
Can you feel the transmission shifting at all? It should only be a very slight change. Again - this is a test of the design, quality and fit of the transmission components.
7. Cabin noise at speed
Is the cabin really quiet at speed? If not, they’ve cut corners in damping and sound-deadening technology and materials.
8. How it negotiates road irregularities
When you go over a big bump or pothole in the highway, are there any noises or loud thumps or clunks? This test usually demonstrates how well designed the suspension is and the quality of damping componentry used in it.
9. Open the trunk and take a look inside
Look at the hinge mechanism and the thickness of the trunk flooring materials. Is the hinge made of thin strips with crummy springs and rivets, or is it a nice hydraulic strut setup? Does the trunk make a “tinny” sound when you close it? Does the trunk lid get completely out of your way when loading the trunk?
10. Open the hood and take a look inside
How thick is the sound-deadening materials attached to the firewall? (the thicker the better). Does the hood make a “tinny” sound when you close it? Are there wires and cables all over the place, or are they neatly routed and clipped out of the way?