LOL i had same thing and i was like.. 'man i WILL start a new game cuz this shit...'
i tried all things u mentioned too
my location was closest to 4 dragons, in Rockshore or something. first i had my BF sadler in there, but then i drove a Vincent in it without knowing there was another car in. i just smashed in the garage and when i got out i 'popped' on the streets.
i tried jumping IN my garage, behind those cars, to push them out, no succes. every time i did that, i got stuck in the middle of the roof, so my legs were in the garage and my chest and head were out of the roof... only thing to do then is RS, or let cops shoot u (it SUX if u dont have any more bullets and the cops dont even shoot you with 4 stars...)
then i tried with a tow truck AND tractor, but my cars were faced with their back to me... so NO WAY i could tow them. i blow them up hundred times with no succes and i really was gonna start over again.
then i took a taxi (not a cab) or a (fast) car but the front of the car may not be too high. i didnt had much space to run in it u know... i smashed on the back of that vincent, and then i saw the vincent comming UP, ON my taxi... i didnt moved my taxi (was still in it) and i saw my taxi 'glitching' (thats what i call it in a way) out of my garage. making abnormal move(s) to come out. but i told u my vincent was on my cab. i thought that Vincent would just fall of but NO, if u try good ull see, THIS is a way to fix it but i tell u, its damn hard and stressy, dont lose patient, u WILL get him out this way (i hope) Well, after 5 times trying that way, (i waited long enough untill the vincent was in a good position so i could get IN) my garage was fixed and now theres only a BP sadler in it
basicly, the vincent stayed on my taxi with its rear wheels. while my taxi was 'glitching' out the garage, he moved the vincent with it. it looked like the vincent was gonna fall off, but he didnt. if u smash ur car onto the car in the garage it wont work, u really need to smash it that way u LIFT that car in ur garage ONTO the car u try this. a low and fast car should do this (with a couple of tries) and u even can get out of the car, if u done it right, the cars will get out.
serious, this works but i dunno if i xplained it well... cant take pics or movies so... let me know if it worked?