i presume you want tips on detailign the engine and painting tailights. to answer the first question, all i can say is just buy a snall brush and be careful
to answer your second question, if you are painting clear plastic tailights red, id suggest just picking up a bottle of clear paint from any paint company, and then before gluing the tailight on to the area, back the tailight with household foil. attach the foil to the tailight with white glue, and then attach the foil and tailight tot he car with white glue. if white glue isnt strong enough, use a *very* sparing amount of CA (superglue) all you need is less than a drop. a tiny little smidgen is enough. i cant emphasize enough how little you need.
anyway, have fun and tell us how it goes