jonathanrn

Hi guys,
I'm getting ready to sell my wife's 2001 RX and of course I noticed some fluid on the garage floor. It's a very small amount, but a leak is a leak. The overflow reservoir is a half an inch below the 'low' mark. Looking at my service receipts, at 128k miles (January 2016), they noticed the coolant reservoir was low and the radiator was filled to the top. They didn't see any leaks so they filled and bled the system. They mention pressure was holding at that time.
So I crawled up under the car and found where I think the leak is coming from. I am attaching a picture. I hope you guys can orient yourselves. On the passenger side of the car sits the oil pan. On the drivers side of the car is another pan (transmission?). It's between the two. I didn't jack the car up so my view was pretty limited. I don't think it's dripping down from up above, but it's certainly possible.
What's the next step? Should I get a pressure tester to see if it will help me ID the leak? I see lots of talk about what coolant to use. Should I buy the pink stuff? Or should I just top it off with distilled water? I'm in the Bay Area with pretty mild weather.

Thanks in advance!!
Jonathan