Can I bring someone with me when buying a car?

Yes, and it's often helpful. A friend or family member can take notes, notice details you miss, and help you stick to your budget and walk away if needed. If you're buying or financing jointly, any co-buyer or co-signer will need to be present or sign documents. A knowledgeable friend can also help with the walkaround and test drive. Agree beforehand on your limits and which questions to ask.