The autoencyclopedia says that you can identify some car malfunctions only by smell. As practice shows, this is indeed the case. If you find new smells in the car interior, then you should treat this fact with the utmost attention. If new foreign odors are discovered, it is important to act quickly.
If during the movement there is a smell of gasoline in the cabin, you should immediately stop and carefully inspect the vehicle. Continued movement in this case can be extremely life-threatening. As a rule, the cause of this smell is a leak that has formed in the fuel system. This can easily lead to a fire and subsequent explosion. It's not worth the risk. The best solution is to call a tow truck and go to a service center.
When the cabin smells of exhaust gases, it is worth checking the exhaust tract. The system could be depressurized. The most dangerous damage here is in the area between the motor and the converter. This is best seen at idle. Breathing exhaust fumes is extremely harmful. They contain a huge amount of carcinogens and other toxic substances. Exhaust poisoning can lead to death, so it is dangerous to drive a car with such a problem.
The smell of burning can not be caught immediately. Often, it can be similar to the "aroma" of burning synthetics. It may indicate the burning of electrical wiring, rubber parts, tires, upholstery fabric, oil, or other machine components. Almost all of the plastic in a vehicle or rubber starts to melt before it starts to burn. If you smell at the melting stage, you can avoid more serious negative consequences. Here, too, it is important to be extremely careful. If there is even the slightest doubt, it is worth checking the space under the hood. There may be smoke in there.
In the event of any incomprehensible smell, in any case, you must stop immediately. It is important to act clearly and promptly. This will not only save your budget, but in some cases save lives.