new car, bluetooth, parking sensors, AC, nice infotainment center, easy pick-up / drop-off, good location right at the airport (no need of a shuttle, which is usually the case in US) friendly and courteous staff, price was unbeatable compared to other companies
need to buy vignettes for different countries (Hungary, Romania), but that is usually the case in Europe; I should have bought a 30-day vignette for Hungary, too, but I bought 2 10-day vignettes, which of course, are more expensive than a 30-day; (it was may mistake, I had rented the car for 10 days, but the vignettes are valid until the end of the 10-th day, not for 240 hours, like the rental car )