From Section BQ of the Service Manual:
The composite body panels of the Elise are manufactured by one of several processes dependent on the requirements of the panel concerned:
- The front and rear clamshells, sill panels, windscreen frame, door outer panels, hard top roof outer panel and front crash structure are produced by Injection Compression System Resin Transfer Moulding (ICS-RTM), whereby a mix of polyester resin and glass fibres is injected into a heated, chrome steel surfaced, closed mould. After filling, the gap between the two halves of the mould is then reduced in order to compress the moulding and ensure complete material flow and consistent structural quality. Panel thickness is a nominal 2.2 mm. The absence of the 'gel coat' used with other processes results in much greater resistance to surface damage, and minimum surface preparation for before painting.
Page 4
Lotus Service Notes
Section BQ
- The front access panels, engine cover lid, door hinge panels, door and roof inners and rear window shroud are produced from Low Pressure Sheet Moulding Compound (LPSMC), whereby flat sheets of composite material are formed using heated, chrome steel surfaced moulds to produce panels with a nominal thickness of 2.5 mm.
- A third process is used for the cabin rear bulkhead, bootbox and radiator mounting panel where the panel surface is not primarily visible. These panels are produced by a Polyurethane Structural Reaction Injection Moulding (PU SRIM) process.
- Body panels unique to the Exige model, including front and rear clamshells, door hinge cover panels and tailgate panel, are 'hand lay' composite mouldings with a nominal thickness of 2.5 mm.
Whichever production process applies, conventional composite repair techniques can be used to rectify structural or surface damage whenever repairs can be determined as being more economic than panel replacement
So the way I see it, the clam shells themselves are polyester, the access panels appear to be somewhat different and could be polyurethane and some non visible parts are in fact polyurethane. But most repairs can be done with conventional polyester resins and fiberglass.
CLW