There are many guarded parking lots and public garages in town, just follow the blue and white P signs! Parking tickets are necessary when leaving the car on the road. These can be purchased at vending machines (you'll need coins!). The maximum parking time is 2 hours. Make sure to pay at all times and avoid committing parking offences, because your vehicle might get a red car wheel clamp which will cost you a minimum of 60 € and a lot of time! There is also a zero tolerance policy towards drink-driving in Hungary and the penalties are very high.
Arriving by car
You can drive to Budapest on motorways M1, M3, M5, M6 and M7. However, you'll need an electronic sticker which you can buy at the border or at gas stations for about 11 € for 10 days.