Just had a look at Auto Route Express and it is 308 miles from Benidorm to Barcelona, but to the best of my knowledge there is a Motorway the whole way and motor ways in Spain are very different to those in England and are not congested at all. It is probably a 4-5 hour journey. Sorry that is the only help I can give you.

thanks a lot maybe if she was desperate to go she could stay the night somewhere and drive back next day eh with the journey being so long i would not think there was any rep trips to barcelona from benedorm then eh

It is the exact same distance as from London to Newcastle and I dont think she would drive to and from Newcastle in one day. If she is really desperate to get to see Barcelona maybe she could get some cheap flights from UK and make it a mini break and spend a couple of nights there.