Inside, Mégane R26.R's cabin carries over the sports calling of its exterior styling, including the use of leather and suede for the steeringwheel and gearlever bellows. Mégane R26.R is also equipped with Sabelt bucket seats and harness belts, and is the first touring car to have aviation-style six-point harness belts as the sole homologated restraint system.

The absence of rear seats serves as a further pointer to the car's radically sporty character which is further emphasized by the numbered plaque fixed to the centre console. A specific numbering system will be employed for each of the countries in which Mégane R26.R is marketed:

- N°s 1 through to 230 for Great Britain,
- N°s 1 through to 126 for France,
- N°s 1 through to 26 for Switzerland,
- N°s 1 through to 26 for Spain,
- N°s 1 through to 26 for Germany.

Intended just as much to be driven round a closed circuit as it is to be enjoyed on the open road, Mégane R26.R can be ordered with an optional four-point roll-cage.