More information on the 2001 ES300 VVT-i Ignition Coil fitment:

In order for these ignition coils to fit, your 2001 Lexus ES300 must have the VVT-i engine. The easiest way to tell is by opening the hood. The big plastic engine cover should say "VVT-i" in red.

If the cover is missing/lost, then look at the front three ignition coils. They should be independent coil on plugs, and should not have any spark plug wires connected to them. The non-vvt-i ES300 uses three spark plug wires connected to the front 3 ignition coils.

Definition of VVT-i: Variable Valve Timing Intelligence