Justsaying – With regard to both your issues it’s clear that you have attempted to resolve them with your Owners Corporation, and as that’s the mandatory first stage before you may then seek to have the issues adjudicated by the Consumer, Trader, and Tenancy Tribunal (in NSW), where you have a couple of choices in my opinion:
1) Make an Application to the Strata Division of the Consumer, Trader, and Tenancy Tribunal (CTTT) seeking Orders from an Adjudicator under S156 of the NSW Strata Schemes Management Act requiring your O/C to make its records of the water samples available to you, and;
2) If the water sampler analyses support a claim by you for recompense from the Owners Corporation (O/C) or its Insurers for the damage caused to your cars whilst they were on the Common Property (carpark), and that’s your intention, then you should send the O/C a Letter of Demand via the Strata Manager requiring payment with say 14 days. If you don’t receive that payment, then you should apply for mediation of your Claim through the Community Justice Centre (in NSW) from where it will be escalated to the Local Court if that proves necessary.
With regard to your second issue of the damage to your courtyard, you are correct in your statement that the O/C is responsible for repairing any damage that arose as a consequence of its works on the Common Property. Don’t “battle” them or offer to “meet them half way financially” but instead make an Application (as above), but this time under S140 where an Order may be granted allowing you to have the required repairs to your courtyard undertaken, and where I think that Order can additionally require the O/C to reimburse your costs; check that first with the CTTT – phone on 1300 135 399