These vehicles are kept in buildings, so I imagine there are some safety considerations (e.g. no fuel and oil) being followed? Are they brought in straight from manufacturing so that there is no risk of oil/fuel in the vehicle?
Here in the States, cars on showroom floors are driven on and driven off. There are large doors (triple wide as compared to normal doors) which are opened to allow them to be driven into position. The only consideration to these vehicles being put on the floor is usually putting some kind of protection for the floor just under the tires. There is a substance in the tires which leaches out and will stain tile floors/carpets. Sacrificial pieces of carpet are sometimes employed, as they are easily replaceable. As for anything human wise, no, there is no consideration for oil or fuel. If you think about it, though, these are brand new vehicles. The only real fear of either of these fluids is if they happen to leak, which you aren't going to find happening with a new vehicle very often. If there is a leak of some kind, you can be darn sure they wouldn't be putting it on their floor until after it's fixed.
NOTE: If you're wondering how I would know any of this, I used to work in a dealership and have driven MANY vehicles on/off the showroom floors.
Although I haven't worked at a dealership like Paulster2 has, I have actually purchased two new vehicles from a dealership in Finland. The cars I bought were stored indoors in a very visible place with glass walls, having new vehicles ready to be picked by the customers!
There are in my opinion two reasons why this is feasible:
- There are huge glass doors, so that the cars can be driven in and out. The doors are open when the cars are being driven in and out. This doesn't leave much room for exhaust emissions to be concentrated.
- The dealers are certainly aware of the dangers. For example, when I received my 2016 RAV4 hybrid, I asked how to turn on the ignition current, turn on the hybrid system, etc. and the dealer demonstrated. After the engine had been running for less than half a minute with the large doors closed, the dealer said "let's turn this off so that the exhaust doesn't kill us". So, they don't just let the cars idle indoors for a long amount of time with the doors closed.
I think this question is similar to "how can a garage possibly be a safe place to store a non-electric car?" -- the reason you can store a car in a garage is that you don't let it idle with the door closed for a long amount of time. When driving in and out, the large door is open.