My petite niece rode rear facing with me until my daughter was born (there are three years between them). At the same time she was not only NOT RF when she rode with her mother, half the time she wasn't in a seat at all.
She *liked* riding RF.
If you want to turn him rear facing, then by all means I strongly recommend it. He really is much too young to be forward facing. Lots of kids fight being in the car seat at this age, so parents think they don't want to be RF any longer and turn them around. The reality is that they simply do not like being restrained, and it doesn't really make a difference whether they're FF or RF. My daughter outgrew all US seats RF by weight at 2 years 6 mos. We had a rough couple of months until she adjusted because she hated being forward facing and literally screamed for the entire trip. She kept complaining that her legs were "stuck". Older, more articulate kids complain that FF their legs fall asleep from lack of support. So your son may actually be MORE comfortable RF.
If he *does* fuss, he'll get over it fairly quickly. You're the mom and your job is to keep him safe. Even at not yet two he understands that much. And there have been many threads over the years with ideas to help you help him over the transition, including singing songs as you buckle to drawing pictures on his hands to giving him a treat when you get to your destination to having a cache of soft car-only toys.
I also recommend getting him a convertible seat like the Evenflo Triumph Advance or the Learning Curve/First Years True Fit. Both should keep him harnessed until he is ready for a booster seat around age 5 - 6. They also both are relatively inexpensive seats that rear facing to 35 lbs.
If you can spend a little more money, the Sunshine Kids Radian has a very tall seat shell, and a 35 lb RF limit. The FF limit is 65 lbs and it also should last him until he's ready for a booster. The Britax Marathon has the same weight limits, but a slightly shorter shell and the topmost harness position is slightly lower as well. However, it can be significantly easier to install than the Radian. The Radian doesn't have high sides, so can be good for kids that like to flop their legs to the side.