We bought our 02 4.4i without heated seats, but I swapped in the better and more adjustable LCI comfort seats with heat, and it was plug and play. Heat works great.

Not sure what your plans are, but the one issue I have with the swap is thst I am getting a pax side airbag light for the occupancy mat. It’s been surprisingly easy to look through it, so I haven’t addressed it yet.

__________________
Current
Original owner 2002 E53 X5 4.4i to 4.6i swap
2026 G80 M3 6 spd
2025 G06 X5 50e
Former
1972 Audi Fox
1986 Saab 900S
1996 BMW Z3
1998 BMW E36 M3 Sedan
2004 BMW E46 M3
2006 Audi A3 Quatro
1993 Mopar 318 Jeep Grand Cherokee
2015 V6 Jeep Grand Cherokee