Ok so please let me know so I can tell my friends. What's the deal I heard it was when you pass 90 days you policy is no good
There is more than one single consideration at play here.
1) Are you in the country legally?
2) Is your foreign license considered valid?
3) Is your DR insurance contract valid and enforceable?
If you are in the country without status (call it illegally, without official status or whatever you want) this supersedes all the other considerations. Your driver's license is not considered valid and any insurance contract you posses is not enforceable.
A Foreign license may be used for a maximum of 90 days by people who posses a visa to be in the country for 90 days. That's the law regardless of how warped its implementation may be in any particular individual situation. Officer discretion (propina) and all that...
Tourists who enter on a 30 day visitor visa may drive for 30 days on a valid foreign license. When your visa expires so does your privilege of operating a motor vehicle in the DR.
People in the DR on a visa that extends longer than 90 days such as students, foreign workers etc. have options that I do not fully understand.
No status = no entitlement to use a foreign license therefore no driving privileges
No driving privileges = no valid and enforceable insurance contract (even if you have paid for it)
No valid insurance = no driving privileges