There's a Car Park on Eccles St between the two Mater Hospitals. Eccles St is directly opposite Temple St., with Dorset St perpendicular to the two of them.
If you're coming from Temple Street, go straight through the junction with Dorset St. and the car park is about 200m on the right. There's pay and display parking around Temple St. but if you don't get a spot try the car park.