The warning lamps are operating correctly...they would signal a problem if the lamps come on when you are driving. The shaky idle, on the other hand, may be the sign of a faulty ignition coil on one of the cylinders...which is common to these, i've also seen cases of defective spark plugs causing a minor engine missfire. There are some vacuum connections for the ventillation system that also detereiorate under the engine cover that causes a shaky idle as well.
Rip
Lead Technician
BMW Factory Training, ASE Master Techinician, Advanced engine performance.
Thanks, let me know if you have any concerns after it is inspected.