—We analyse mobile propagation channels which occur in the context of car-to-car communications in the 24 GHz ISM band. From the information gathered, we design robust frame designs for combined radar and communication systems using high-bandwidth OFDM signals. Two solutions are proposed: the combination of a spread spectrum technique and a standard convolutional encoder, as well as a low rate Reed-Muller code. We can show that while both perform well enough for the channels analysed, the Reed-Muller code has some advantages for the RF system, but achieves lower data rates.