I'm planning on ordering the car with the factory hardtop. Other than that, probably not many real mod.s, aside from:
Add a fire extinguisher (many in England mount theirs above/forward of the passenger footrest)
At some point, depending on the standard exhaust, may have to go with an aftermarket or a Lotus "sport" exhaust.
Also down the road, and probably around the same time as any exhaust mods it may make sense to enhance the intake with a higher-flow air filter.
As far as tire changes, will have to see what we get, I guess some in England really like the Yokohama Advans tires as an upgrade.
Covered in Brandy and Lard