ok so my fav car of all time has to be the BMW M3 (e36) but since i dont have that kinda money
i was thinking a replica 316 or 318

i really want a 318is but since im a 1st time driver (17) the insurence is to high

and i heard bad things about the 316

so should i just save my money or go for a 316

also any info on these to cars would be great(running costs, etc.)

If you get a BMW it is better to get a 3 series. But please be forewarned that BMW's are very expensive to work on and very expensive to repair. If I were you I would stay clear of them all together and get a Honda or a Acura.

ok, if you're looking to save money on insurance, well definately go for the 316, as it is in a different price bracket and is cheap enough to insure.
As for the bad points of the 316... well they are the same as any bmw, very expensive to repair + fix...
It also really depends on the BMW's history completly, if you can find a good 316 (preferably with low enough miles) with full service history + well maintained, they can be a gem!
But this is rare enough, as if someone owns a perfect bmw, they will rarely part ways from it...
When choosing a secondhand bmw (presuming that you are going for a secondhand one 97-01) you would really want a professional to go out and check the car with you.

since the 316 is a strong heavy car, petrol would be expensive if you drive it hard, if not it should be ok.

but yeah, for your age i think the 316 would be the way to go.

Whatever the total purchase price is, double that prior to purchase for everything that is going to go wrong with the car. Most people that buy a used cars can not afford to maintain them....regardless if it is a BMW or not. Have enough money to fix its issues. Buying used / older (1990 to 1999), be prepared to flush the tranny, brake lines, and change the pads and discs, flush the radiator, change the struts, inspect the transmission mount, the drive shaft flex joint, change the a/c micron filter.....do all of these things before you start driving it. It will enable you to be familiar with the car, rule out any of those things going wrong and make it safer.