Basically, there isn't any. 

Across the street from there are some two-hour parking meters, and further along the road there are some five-hour parking meters.  Most of these are permanently occupied with residents’ cars so if you get one you are lucky.  There is a delivery bay, big enough for two cars, between the two sets of meters.  The police are fairly active in this area so it’s best not to park illegally and, if you do get a meter, don’t forget to put some coins in it.

The street that leads from the Kiang Wu roundabout to the back of St Paul’s ruins (Rua de D. Belchior Carneiro, “Goh Yuen Gai”) has quite a few parking meters and often some of these are vacant. And if you carry on along this street into the cul-de-sac behind the ruins, there is a pretty good chance.

A recent addition to car-parking spaces in 'downtown Macau' is an open-air carpark on Rua dos Mercadores ("Ying Dai Gai"), on the left-hand side about 400 yeards after you've turned off Avenida de Almeida Ribriro (San Mar Lo").

The closest multi-storey car parks are:

Behind the Leal Senado/IACM building on Avenida de Almeida Ribeiro ("San Mar Lo"), entrance from Rua Central (“Lung Chung Gai”).  There’s a digital sign at the corner of San Mar Lo and Rua Central that tells you how many spaces are vacant, hence whether it’s worth turning in.  The sign usually says “FULL”.

Behind the main branch of HSBC on the Praia Grande (“Nam Wan Dai Mar Lo”), entrance from Calçada de São João (“Dai Tong Cheah Hong”), opposite the end of Rua Formosa (“Mei Lai Gai”).