If you decide to continue with mechanic job, then you can get your own yard (rent empty plot from some mdosi) or partner with someone (share the rent but everybody do their own stuff).
- At the garage, setup an auto-shop, stock it with basic, common parts for common cars (filters, plugs, oil, bulbs, brake pads etc)
I like the rebuilding old car and selling idea. It's exactly like the importing and selling idea where the margins are almost the same i.e. 30-60K profit.