Hi,
I think you'll find that you have to have your dog safely restrained when in a car in the uk, so a harness connected to the seatbelt is adviseable at all times.
I don't think "tie her collar" would be acceptable or safe for your dog lol

but I'm sure you didn't actually mean that lol

Below is the actual requirements for the UK
"In the UK, while there isn't a specific law outright banning dogs in cars, it's crucial to ensure they are suitably restrained to avoid distractions and potential harm to themselves or others. The Animal Welfare Act 2006 requires owners to ensure their pet's welfare, and neglecting this can lead to prosecution."