Hundreds of tax-defaulted properties across San Diego County are headed to the auction block next month, with officials opening registration for interested bidders. The County Treasurer-Tax Collector’s Office said 686 parcels will be offered during the annual online sale, scheduled for March 13 through March 18, Fox 5 San Diego reported . To take part, prospective buyers must complete the online registration process by March 3. The properties up for grabs have been delinquent on taxes for at