yes, im afraid so, in order of commonness,
1 Hbv, youve done.
2 Oil cooler cover plate, coolent bridge, stat housing all in the v of the engine.
3 metal coolent transfer pipe above bell housing, it has a piggy back smaller pipe to hbv( i think) welded on to it.
4 core plugs to cylinder head, usually around the pass side bank by dis pac.
You may find viewing easier with scuttle and wiper mechanism removed. But if its not hbv? Or associated pipe work? Then its plenum off, inlet and fuel rail off, black plastic inlet manifold off, and under there you will find list no2.
The fact yours is drivers side "might"suggest its not core plugs, which is a real pig as the heads need to come off to fix. In which case a bottle of bars stop leak is your only hope, but only use one bottle per system or you risk a blockage.
Ps you may be able to see in under the plenum with a small torch, only real place to see is under throttle body between the 2 plastic inlets or round the side by the egr valve. Your looking for any residue/chalky evaporated remains of what ever colour your coolent is. Any leak will flow back to the rear of the engine usually.
Hth