If it is between the tires and the passenger compartment, heater core or the hoses to it are leaking.
If it is front of the tires, probably a hose on the radiator.
2005 Elise - Nightfall Blue
Purchased 11/2015 w/:
DBA4000 w/ Stainless Hoses
S111 re-ENFORCER, DSbrace
Alpine Type R, JL Audio 2 Speakers
Odyssey PC925 in Rennline EL41.35 Box
Cup Intake, Katana2+
RLS ExtendView Mirrors
OEM Harness Bar, Schroth 4pt Harness
Pioneer AVH-X7800BT w/ AVIC-U280
BOE Clamhinge w/ Radium Shims
2011 Mustang V6 Kona Blue
Lots of Mods