I think it's over-simplifying by expecting a bank to directly sanction a 35-year car loan by re-mortgage.
What happens is these people buy the house and pay the mortgage. They then take out the car loan. Insurance costs a grand and goes on the credit card. Sure I'll clear it when I get my bonus. Bonus is spent on a 3-week holiday in Thailand, along with another 1k on the CC. Sure I'm due a pay-rise in May. Pay-rise comes and goes with rising interest rates and fuel costs, etc. Oh, and we need that 42" plasma screen TV too.... throw it on the CC. Short on cash at the end of the month, throw the weeks shopping on the CC. Get paid but last weeks shopping isn't paid for until the CC bill comes and cash is running short again cos it's nearly the end of the month. Take out a personal loan to clear CC and start afresh.
Rinse and repeat above for another year or two.
Go back to bank and tell them you're building an extension/attic conversion and ask for an equity release. Bank manager closes his eyes when he asks to see your architects drawing and you show him a blank A4 sheet. No worries, we can release €50k for you Mr & Mrs X, sure isn't it your own money anyway only it's tied up in bricks and mortar!
Rinse and repeat....
Believe me, this happens. Came close to this sort of scenario myself, only I got sense (thanks in large part to AAM!), sold the 03 car and am now tipping around in a rather banged-up 93 Toyota Starlet.
My next car I'm buying with cash.... my own cash....