Synopsis As Introduced Amends the Code of Criminal Procedure of 1963. Provides that if a defendant is accused of an offense of driving under the influence or aggravated driving under the influence as defined in the Illinois Vehicle Code, and if the defendant refused chemical testing requested by a law enforcement officer, evidence of the defendant's commission of another offense or offenses of driving under the influence or aggravated driving under the influence is admissible, and may be considered for its bearing on any matter to which it is relevant. Provides that in weighing the probative value of the evidence against undue prejudice to the defendant, the court may consider: the proximity in time to the charged or predicate offense; the degree of factual similarity to the charged or predicate offense; whether the predicate offense resulted in a finding of guilt; or other relevant facts and circumstances. Provides that if the prosecution intends to offer this evidence, it must disclose the evidence, including statements of witnesses or a summary of the substance of any testimony, at a reasonable time in advance of trial, or during trial if the court excuses pretrial notice on good cause shown. Provides that proof may be made by specific instances of conduct, testimony as to reputation, or testimony in the form of an expert opinion, except that the prosecution may offer reputation testimony only after the opposing party has offered that testimony.