I tried a bunch of new fobs offered for around $25 on ebay. None of them worked. The receiver gets a good signal (tested with a scope), but either the transmitted code is not accepted by the BCU or the timing is not accurate. They don't use a crystal as timing device like the OEM fobs. All are the same cheap knock-offs with two chips only. Some vendors don't bother to use pictures of the OEM board while you get a knock-off instead.

Also I tried 433MHz. The reason for converting to that band: less crowded (lots of TPMS, garage door openers, alarm systems, weather stations and other crap on 315Mhz, while 433Mhz is quite new in US) and the fobs are allowed to transmit with more power (5dB more, so you could get almost double range in theory). I got a 433MHz receiver from ebay Europe and 433MHz fobs. The signal looks good at the receiver but none of fobs could be programmed, very likely for the same reason.

Bottom line: get either a new OEM (expensive) fob or find a cheap used one. I got one on ebay and it took me 2 minutes to program it with the nanocom. Unfortunately there are no used 433MHz fobs to find in the US.

 

I used these guys. Easy and relatively inexpensive

https://remotekey.co.uk/land-rover-k...-1999-to-2006/

 

I saw this, but I didn't want to spend $200 for a pair of fobs. The 433MHz receiver was only $15. Maybe I'll find some cheap used OEM fobs later.