I've investigated quite a number of shootings, and seen first hand, where rds went thru the front, sides and rear. It's possible you may get some from the inside. It wouldn't be much from the front windshield as the windshield is laminated glass. Side and rear might get some falling back inside. The backward flow of glass happens just as the bullet strikes the glass. It's not much but some where if you were close enough to the glass you might get some on you. However, you have to look at the big picture. Why are you shooting out thru the glass? It's because you're being attacked with deadly force and you are defending yourself. So in the big scheme of things a bit of glass on you and hearing loss are pretty insignificant compared to fending off incoming rds.
Most of the shootings I've done have involved 9mm. Here's a short recap on a few:
1) Attempt to arrest a bad guy sitting in a car. BG, armed with a Browning HiPower loaded with Fed 115 gr BPLE, shoots 1 agent who approached the driver's side window. Window down, agent hit and killed. 2nd agent approaching from the passenger side front with an 870 is fired on thru the front windshield with 1 or 2 rds. Both rds go thru the windshield. 1 strikes the agent in the head with a glancing hit. Agent drops but then gets up again as BG is rolling out the driver's side door. BG fires 1 or 2 rdsthru the front windshield (there were 3 rds total fired at that agent, just never sure of what order) striking the agent in the wrist which the rd travels up his foream and exits near the elbow. That agent is down and out of action. 3rd agent, armed wtih S&W 439, fires 8 rds of 9mm Fed 115 BP thru the back window. All 8 rds to thru the back window and window stays intact. All of those rds miss the BG. 2 of those rds, after going thru the back window continue on thru the front window. BG finally killed by 1 shot from a 12 ga slug.
2) BG, armed with a .22 S&W revolver, fires at officer who is armed with a S&W 439 loaded with 115 gr Fed BP. Officer fires 8 rds at BG who is seated in the front passenger seat of the car. Officer is in front of the BG's car so is shooting towards the front. None of the BG's rds were found so don't know what they hit. BG is firing as he's rolling out of the passenger side open door. 3 rds from the officer hit the windshield where the dash meets the windshield. All 3 rds penetrated the windshield and lodged in the dash. 1 rd went thru the passenger side window shattering it. 1 rd when thru the headlight and lodged in the fender. 3 rds went thru the side of the open door. One of those rds that had gone thru the door struck the BG as he was squatted down in the leg near the knee, exited, traveled up his leg under his pants leg and causing a cut along the thigh, went thru the cheek of his buttock, and lodged in his wallet.
3) BG gets out of his truck and fires on the officer who is parked behind the BG's truck. One of the BG's rds (forget now what the BG was shooting) hit the officer. BG gets back in his truck to drive away. Officer fires with a S&W 459 loaded with W-W 115 gr JHP+P+. One of those rds goes thru the back window (window stays intact), goes thru the headrest, and strikes the BG in the back of the head.
(I always like telling this next one)
4) Officer is patrolling one quite Easter morning out in the rural part of the county. He sees a coyote off to his right. He pushes the button to roll down the front passenger side window to shoot the coyote. He fires thru the front passenger window and misses the coyote. However, when pushed the button to roll down the front passenger window he mistakenly pushed the button to roll down the rear passenger window. That cost him some days off.