Insurance is an ongoing problem for all of us, especially young ones.
My advise, everyone should be insured and do it legally, if you cann't afford to insure a modded car, then don't mod the car, its not worth it and you'll and up spending alot more than you planned.
For the cost of doing things properly, its alot cheaper than getting caught out in a accident that could cost tens of thousands and finding your insurance is void, in this day in age, its easy to rack up a big accident bill.
My two cents