Father in law had a garage like that - they were built when cars were a lot narrower overall, he could just get a modest modern car in and open the door enough to get out as long as there was nothing else along the sides of the garage.
It strikes me that you should knock it down and start again, and build either a functioning garage - a bit wider perhaps - which can be a workshop as well, or a purpose built workshop. One issue might be the roof - if its corrugated cement it might have asbestos in it which can push the disposal cost up. I suspect thats why so many people just leave fairly useless garages alone to rot in peace.
3 questions to think about:
- will you ever want to use it as a garage ?
- if you don't have a garage will it detract from the value/saleability - you will move out one day even if its years hence
- are there any planning issues if you demolish the garage and build a workshop?
Many years ago a friend applied for PP to build a workshop in his large not-overlooked garden. It was refused. He then reapplied using exactly the same plans but replacing the word workshop with "hobby and storage area". Approved.
A neighbour has recently converted his garage by keeping the up and over door at the front and building a stud wall about 6ft back. That gives him room for bikes and bins through the front and a nice draft free workshop behind. Any future owner could take the stud wall out if they really wanted a garage. Struck me as a sensible solution.
New house, first house, very exciting times - enjoy. I moved from a flat to a 1910's 3 bed semi in 1976 - that's when the learning started.