待我有车时开着毛驴逛天下
[dài wŏ yŏu chē shí kāi zhe máo lǘ guàng tiān xià]
It's an expression of a leisurely dream to travel when one has achieved certain material success. But there is an element of contradiction because it juxtaposes modern elements (cars) with ancient methods of traveling (donkeys). It could be used humorously, to highlight cultural clash or simply a fun aspiration.