How to add bars or strengthen a sliding door?
If youre worried about someone breaking a glass door, stop.  First of all, there are much simpler ways to de-track a slider. Second, you can put all the bars you want on the door, but the thief can still break the glass and reach inside to release the lock &amp; catch.  

Similarly, garage doors are by design (for lightweighting) easy to crumple or kick in.  

The simple fact is that a determined and experienced burglar knows more ways to get in, without doing significant damage or making noise, than you can imagine.  Unless your neighborhood has a history of breakins, it's not statistically worth while to take any extreme measures.  If anything, install an alarm system with automatic calls to first responders.