I have agreed to part ex my vehicle with a main car dealership, we agreed a fee, I signed a 'sale declaration' which is basically the details of car I'm purchasing, and I signed a 'trade in declaration' which is my vehicle details are all legit and correct information I have provided.. I have agreed to come back to the shop to complete the exchange, I have now changed my mind though based on revision on internet and realising I'm being short changed, they do not have any of my bank details, only contact number and address, I have not paid anything as of yet,
Will there be consequences were I to back out?
Thanks for any help

If it's a brand new vehicle you purchaced and have actually driven off the lot... yes... if it was a used vehicle you bought... then maybe or maybe not depending on the paperwork.