On some points however, the commission was still dissatisfied. Firstly, it insisted on a front-wheel drive. As deliveries would be delayed by its development, it was accepted that the first batch would lack this feature, but possible later batches should have an improved 6x6 drive system. A second improvement seen as necessary was the use of bulletproof tyres of the "Cellastic" cushion type. Since these would increase resistance by about 20%, a presumed stronger Ford 125 hp Lincoln-Zephir V8 engine should be installed. Minor changes included a coupled dual drive, an improved differential, a rubber-suspended engine block, improved ventilation and adjustable seats. DAF tested the "Cellastic" tyres in October; it was shown that performance did not suffer but that the tyres themselves were prone to deformation after long periods of high speed driving. For this reason it was decided to postpone the choice of tyre type.