Hi, I'm currently work then now. Much like your friend I had a horrible APR with santander (19%), but my original plan had been to refinance I. a year. 6 months later I tried torefinance but the offers were not much of an improvement so I held off. 2 months later I got a letter from carfinance claiming they could lower my interest as low as 12%. So after some research turned up no red flags (for me at least) I applied and was given like an 8.8%. This all happened early 2013, bank then my credit was like 600.
From my experience they are worth the inquiry and give reasonable rates for low credit. If he/she has paid santander well has reasonable income and stable job/residence if imagine they'd get it.
