We have reported elsewhere the discovery of apparently
high-degree nonradial oscillations for the four rapidly rotating (-120 kms^-1) δ Scuti stars: 21 Mon, κ^2 Boo, ν UMa, and o Eri. Here we discuss some of the techniques which we have used to isolate and to analyse the time varying components (-1% continuum) of the line profiles. They are best seen after subtraction of an average, filtered spectrum. For the δ Scuti stars, periodograms of the residual spectra show several peaks, some of which can be identified with the degrees of oscillation found in our preliminary analysis. In the latter, values of |m| were estimated from the sub-feature accelerations and delay in transit of the features. While one mode tends to dominate it is clear that often more than one Is present. The sub-features are not always equally spaced and they can show phase changes and doubling. While nrp provides an adequate, general description of the phenomena, we are probably seeing only part of something more complex. The immediate challenge is to combine the results from many lines plus higher spectral resolution to improve the visibility of the time varying features by at least an order of magnitude.