Another 130i in Melbourne here.
I'm keen to start a group of us to meet periodically (every quarter?) and do whatever basic servicing is required, eg fluid changes, filter changes, brake pads, anti-squeek solutions etc. The idea is to get together, share knowledge, share tools (eg oil filter wrench), get to know the cars a bit better, save a lot of money.
Apart from the regular maintenance items, many on the forum have had success with the CDV delete and clutch stop - we could make a day to group buy and modify? Also, there have been discussions on the best fluids for the gearbox (redline?) - same deal.