In federal court (and under state rules of evidence based upon the Federal Rules of Evidence) this is governed by Federal Rule of Evidence 801(d)(2) which states that:
A statement is not hearsay if:
The statement is offered against a party and is (A) the party's own
statement, in either an individual or a representative capacity or (B)
a statement of which the party has manifested an adoption or belief in
its truth, or (C) a statement by a person authorized by the party to
make a statement concerning the subject, or (D) a statement by the
party's agent or servant concerning a matter within the scope of the
agency or employment, made during the existence of the relationship,
or (E) a statement by a co-conspirator of a party during the course
and in furtherance of the conspiracy. The contents of the statement
shall be considered but are not alone sufficient to establish the
declarant's authority under subdivision (C), the agency or employment
relationship and scope thereof under subdivision (D), or the
existence of the conspiracy and the participation therein of the
declarant and the party against whom the statement is offered under
You don't need to economically benefit from a crime to be a co-conspirator. Overt acts in knowing furtherance of the crime are sufficient, and an "accessory after the fact" meets that requirement. But, a statement made when caught during the commission of another crime is not a statement made "during the course of and in furtherance of" the conspiracy.
Not all states have adopted the "during the course of and in furtherance of" requirement in their version of FRE 801 (although I don't have a reference easily at hand to tell you which ones do and do not have that requirement). But, for MBE purposes, the Federal Rules of Evidence are the majority rule which is used.
Of course, if the driver testified in court to what he told the police, that wouldn't be hearsay, because it is a statement based upon his personal knowledge. The fact that the police are relaying what the driver said is what makes it hearsay.
Furthermore, if the driver was compelled to testify (perhaps with a grant of transactional immunity to avoid 5th Amendment issues or following a guilty plea by the driver to being an accessory after the fact) and lied, the statement made to the police could be admitted, not for the truth of the matter asserted (which would be hearsay), but to impeach the driver's trial testimony (which would not be hearsay).