In Europe, parking tickets are also heavily used. In Sweden, parking violations on street are considered traffic crimes with a fine. If the fine is not objected or paid within a specified time, the Swedish Enforcement Administration will claim money from bank accounts or other assets, relatively fast. The owner will be noted as a bad payer, and will not get a loan or a new rental apartment etc. for three years. A parking violation on a parking place (not on the street) is considered a break of contract which results in a penalty fee with different rules. According to statistics from Stockholm the cars with the highest number of parking violations (weighted for number of cars) are Jeep, Mercedes-Benz, Porsche and Lexus. Mercedes owners were the worst for parking in handicap spaces. Professor Gunnar Aronsson at the department for psychology at Stockholm university believes this is due to the owners being well-off and thinking that their time is more important. According to Jan Prestberg at the traffic office in Stockholm the fines are low enough to be ignored by richer people. It is often hard to find parking spots in big cities. After wheel-locks were introduced in London, the prices for rented parking spots went up considerably.