What Bill of sale (logbook loan) means for you
A logbook loan is money borrowed against the car's V5C, and the lender may still have a claim on it. Under the Hire Purchase Act 1964, a private buyer who buys on hire purchase or conditional sale in good faith usually gets good title, but that protection doesn't cover logbook loans.
The V5C shows the registered keeper, not the legal owner, so it won't reveal a loan. Run a Finance & Stolen Check (£4.99) or a Full Check (£9.99), which also covers finance, before paying. If the loan isn't cleared, walk away.