Sorry if I wasn't clear.

When the same model has separately offered trim or version levels - e.g. SE and M-Sport, and both are separately listed on the Calculator then you are right, different OMSP's, depreciation codes, etc can apply to models that are substantially the same and this can mean that there are anomalies such as the one you suggested.

What I was referring to was the example of the M-Sport Plus pack mentioned by 318 IS Cosmos. This is an option pack, not a distinct trim level. In the case of options, or option packs, the Revenue will add to the trim level OMSP a proportion of the original cost of the options or packs. In the link I posted a few posts back on page 6 you will find the details of how they determine the proportion of the original cost of the options to add to the OMSP.

An example, in the run-out phase of the F30 BMW offered an M-Sport Shadow Edition trim level that had a good few extra features over the std M-Sport spec and was treated by BMW as a trim level (with a published list price) rather than a customization of an M-Sport by adding options and packs. If you look on the Calculator you will find some models that have a Trim Level of M-Sport Shadow Edition, e.g. a 330d, but not one described with a trim level of M-Sport Plus.