You wouldn't get the same experience as it is rumbleing your stand not your body.
As some know this is an area I have done a lot of testing/messing around with...
Buttkickers or tactile units dont always have to go to your backend or indeed rumble your entire body.
Their are several things he could do and it will bring much added immersion...
Im hopeful we will begin to see more people get into "Tactile Immersion" as its very underestimated or ignored...
1) Simply cut or remove the under lining of the chair and mount a BK to the wooden frame of the chair. This is often done on sofa's in peoples living areas/cinema rooms. Then restabled or stitched back on and a bit of cable tidying.
2) Instead consider cutting some 1" thick wood sheet to an appropiate size and use this as a platform for the chair and wheel stand to secure too or sit on. Attach a Buttkicker to the wooden platform under the seat area, it will vibrate if you get a decent model (not the gamer ones they arent as strong or as good).
3) Consider using the Mini LFE Buttkickers or Clarke TS209 tactile units. I found these offer very good performance for the price. Instead of buying the official BK amp buy like I have cheap 2nd hand AV Reciever on an auction site but importantly get one that allows the 4ohm speaker rating and preferrably PL IIx Decoding. Many use 8ohms so look for a feature usually listed as 4ohm switchable. You can use this in conjunction with your audio using PS3 Multi AV output mode. With a decent AV Reciever he can power more than one unit and personally I would recommend he gets 2x Mini LFE Buttkickers.
With two units it is possible to use one under the chair in it or on the platform from the LFE bass channel and the second unit at the pedal section. However with this run that from the AV Recievers CENTRE channel not the LFE. Why, well because with this combined with the one on the LFE it will give additional independent feedback for good immersion both from rumble strips, crashes etc but also the revs of the engine and backfire of exhausts from cars ahead of the players car in game. These can now all be felt in the pedals at the front coming direct from the CENTRE channel of the AV Reciever. Its pretty cool.
If he is interested or others are Ive no problem helping out but lots of you wheelstand guys could indeed benefit loads from tactile and a bit of simple d.i.y. Dont know what your missing lads...