I never feel comfortable driving someone else's car.

I was brought up with huge respect for other people's stuff in general, and my father's cars in particular, well aware how careful he was with them.

While I was irresponsible as hell with everything else, I had enormous respect for them. He let me use both his 964 Turbo and his Audi whenever I wanted to - I never chose the Turbo unless he was with me.

 

As others have said, you know your son best so only you can decide if he should or shouldn't drive your car.

I'm a life-long car guy, I was driving my mom's car with my dad in the passenger seat at 12 (Sunday empty parking lot). My parents let me drive my mom's Z28 at the age of 16 and I never breached their trust.

My eldest son aged 14 could care less about cars, my 12 year old daughter too but my 5 year old son inherited my passion and I'm sure will be asking me to let him drive just as I did with my dad.

 

My eldest daughter is 16 and just learned to drive a few months ago. She has her own car; a highly modified mint condition 1982 VW Golf cab (blueprinted euro gti engine, suspension, etc...) that I've owned since new and preserved for her. I figure it's a great car for her to cut her teeth on and in a few months, I'll take her out for an intro lesson in the p-car. I intend to have her attend some performance driving courses before she solos in my car though. My plan was to spoil her for life by introducing her to fine automobiles so she never settles for a POS later in life...no matter her budget.