The evidence is likely to be admitted because it is reasonable to believe the vehicle contained evidence of the arrest
According to Grant decision, Police could only make a direct arrest if the suspect has a continuing threat to their safety posed by an arrestee,
Whenever police respond to a request to go into the crime scene, the department would provide them with a general description of the situation (such as the description of possible perpetrators or how dangerous the situation is)
The handgun possessed by the robbers in this situation is considered as something that has a continuing threat to their safety. Therefore, the physical evidence recovered would most likely be admitted.