I just installed the 99 spec lip. I did a search and I didn't find any threads similar so I wanted to post my experiences. The install was very easy and took about 1/2 an hour. You need to use a exacto knife or a utility knife and cut off the points and tabs that stick up from lip. I don't have an R1 Lip so I used the other plastic lining to match up the holes. In all I had to drill/cut 2 new holes in each piece, the 2 closest to the wheels. The fit is very good with the exception of the edge by the air holes which stick out slightly. IMO, on a scale of 1-10 with 10 being the hardest this was a .5 or 1.

If anyone has any other info to add please do. Hopefully anyone doing this install in the future can find some use from this thread.

 

It's a toss up for me to go 99 J-spec lip or go with the more rounded R1.
Did you take pics during the install? I heard it overhangs a bit into the fenderwell each side about a 1/2". Do you have to pull the black lip off a base FD before installing?

 

I might eventually go with an R1 Lip, to be honest I had some money that was burning a hole in my pocket so I had to buy something and that turned out to be the 99 lip.

It does overhang slightly into the fender well probably 1/2 an inch or so. I think it looks good though. Unless you are familiar with the different lip it really doesn't look it wasn't made for an earlier model. I pulled the old lip off but i'm sure you will need to pull it off anyway, I don't see how it would work with both.

 

Yes you will have to remove the base spoiler off before you can add this one. Overall the fit isnt too bad, just a couple minor places like JBC mentioned. Guess what! I have pictures!

Here's the overhang.

 

Here's the only real part that doesnt fit right. I thought about taking a heat gun to it and heating it till it started to melt just a bit, then pull it back so it fits evenly, but I dunno. Maybe I'll try it one day.

 

And the view from the back incase that helps any.