Adjectives conventionally take the following order: opinion, dimension, age, shape, colour, origin, and material -- so we should say "exotic, imported, dark red, sports".
2. Passive voice:
Since we do not have an explicit subject, the verb should be in the passive voice ("was being driven").
4. Verb tense:
The activity occurred in the past and driving is an activity that extends through time, so the past progressive tense is probably best: "was being driven".
5. Word confusion:
"To" is a preposition. In this case, we want to use an intensifier: "too".
6. Word confusion:
Be careful not to confuse "of" and "off".
7. Verb tense:
"It'd skid" means "it had skid" (or "it would skid"). Since we want to say what happened at a particular moment in time ("when"), the simple past is probably best: "skidded".
8. Verb tense:
Again, since these events happened in the past, we should use the simple past tense: "was".
9. Word form/order:
“Serious” is an adjective. We want to describe the verb "injure", so we need an adverb: "seriously". Also, note that the adverb is usually placed in front of the verb (not after it): "seriously injured".
Adjectives combined in a series should be separated by commas. Also note that "two young women" is an appositive, so it also needs to be separated with commas.
The exotic, imported, dark red, sports car was being driven too fast when it skidded off the road, and the passengers, two young women, were seriously injured.