Yes, some people advise against buying a BMW or Mercedes when purchasing a new car, but it largely depends on individual priorities and preferences. Here are a few reasons why some people might say this:

1. Maintenance Costs: Luxury brands like BMW and Audi can have higher maintenance and repair costs. ανταλλακτικα Audi classic and servicing may be more expensive compared to non-luxury brands.
2. Depreciation: Luxury vehicles often experience quicker depreciation, meaning they can lose value faster than some other brands. This might be a concern if you plan to resell the car in a few years.
3. Insurance Costs: Due to their high value and repair costs, insurance for luxury cars can be more expensive than for regular cars.
4. Reliability Concerns: While these brands offer cutting-edge technology and performance, some models have faced reliability issues, which could mean more frequent repairs.

However, BMW and Mercedes are still highly regarded for their performance, luxury, and advanced features, so it ultimately comes down to what you value in a car!