I have a 98 sc2 with about 157,000 miles that has an inconsistent coolant leak.
Leak size on ground range from a couple of drops to 2''x2'' spot.
The idiot light does not always come on.
It appears to drips from somewhere above or around the the RH side of the engine. The drip shows up under the RH front A arm and plastic shield that covers underside of radiator.
I replaced the radiator and hoses about a 3 weeks ago.
Any advice would be appreciated.

Check the radiator coolant bottle. Make sure 1) the coolant cap is working properly, and 2) that the coolant bottle is filled to the proper level. Overfilling the bottle could cause the marks you mention ...

Thanks for the suggestions. Root cause of problem leaking water pump. Potentially caused by new radiator = increase pressure.

Glad you located/fixed your problem. Hope 2009 is a good year for you