The -01e's rear end bodywork is largely redesigned.
The rear fender. Note the outboard trailing edge fender is taller than the inboard. We've noted that Audi, Peugeot, and Lola (Rebellion) have run gurneys in that area and understand it is profitable aerodynamically.
The -01e's legality louvers.
The
legality cheese wedge bolts inboard to the outer tunnel wall and is
secured outboard via brackets. Note the cutout in the outboard
surface just above the mandatory cheese wedge: Art 3.4.1 c/ states:All bodywork behind the rear wheel centerline and more than 200mm above the reference plane must form a smooth, continuous, unbroken surface without cuts, and be visible from above the car with the rear wing removed. Vertical surfaces are allowed so long as their entire top edge is visible from above.
And the top edge of the cutout corresponds with the start of that 200 mm demarcation, especially considering the cutout aligns with the height of the trailing edge of the cheese wedge; the cheese wedge's max height is 200 mm.
The diffuser strakes are trimmed short of the diffuser trailing edge. We noted similar on the ARX-02a LMP1.
Highcroft
experimented with at least three engine cover trailing edge solutions
over the Sebring 2011 weekend. Standard gurney here.
Reduced height here, high in the middle.
This bolt-on solution eliminated the gurneys and increased the camber of the trailing edge.
The rear wing is borrowed from the ARX-01c, the clue being the upturned out board main plane section. 
The -01e's swan neck rear wing mounts are adopted from the ARX-02a's. 
The leading edge fillet attaches the endplate to the engine cover.
As on the -01c,
the brake duct intake has been moved from the lower quarter panel ahead
of the rear wheel to the leading edge of the rear fender.