Ask Jay Leno: What's my Porsche worth?

Each week, Jay Leno answers questions sent in by viewers. Tune into "Jay Leno's Garage" for the first episode Oct. 7 at 10 p.m. ET/PT on CNBC.

In 1947, Porsche began engineering its first sports car — the 356. For nearly 20 years, it was the flagship vehicle from the famed German automaker; today, they're worth silly amounts of money.

As in hundreds of thousands of dollars.

In 1972, Bob Lane — owner of RWL German Imports in Atlanta, Georgia — finally got his hands on one. He traded his 1962 Super 90 Porsche motor for a 1956 356A Speedster, and has spent the past 40-plus years working on it.

Lane has chalked up more than 400 hours and $50,000 restoring his classic car, transforming it from a rusted-out shell to a functioning machine with a showroom shine that's worth more than $400,000.

But he's also added a few modern improvements, including disc brakes and a 12-volt system — modifications that some purists might not necessarily appreciate.

Here, Bob asks Jay Leno about how those modifications will affect the car's value.