first mods for 99 cobra?

ok gears will be your best place to start. dont do anything less than 4.10's. I wish I had gone with 4.30's. and mine is a daily driver 7 days a week. port and polish intake, subframe conectors, get and irs brace and some irs bushings to help with wheel hop. if you dont care about the ride then switch to a solid axle. there are a ton more mods and I am sure you will get lots of replies.

Get a shifter, then gears, then H pipe. That should get you on your way. After that, I guess it depends on what your plans are for the car. Good luck.

get some pullies
headers and an off road x-pipe
nittos DRs

Get a 125 shot of NOS. My best at the track last nite was a 13.5 at 112mph with the spray. Times suck. No traction with stock tires and gears. I am going with the Nittos next time.

12's with 410's & DR's. Mine went 12.86 @ 105 w/1.78 60' when it was on a prepped track.

My best last year was a 13.2@108 bone stock sans Pro5.0 shifter/125 dry shot. I blew my clutch on that pass.

If you do highway driving often, you may get tired of the 4.56 gears...at least I think I would. I now have 4.30 gears....BUT, I have a Viper T56 with a big .50 6th gear....I can cruise at 75mph at 2100 RPM's.

4.10's minimum though...I'd say 4.30's.

3 things I'd do right away:
1. replace the mid pipe...off road pipe preferably.
2. aftermarket shifter, such as a tri-ax or pro5.0. Prevent missed shifts and safer on the trans too.
3. a set of drag radial Nitto 275/40/17 tires.

First time to the track with the IRS...I bet your first pass is in the low 14's....then down to a 13.7 or so. It takes a good driver to be able to ride out the clutch and not wheel hop (which will/can destroy your 1/2 shafts) and get low 13's or high 12's with a bolt on full weight Cobra.

To get 12's n/a you will need full exhaust, CAI, pulleys, MAF, tune, sticky tires, and the balls to rev it up (pray the clutch and 1/2 shafts hold) and go for it.