Are you looking for cheaper car insurance for your RS500 or Escort Cosworth, then try some of these Insurance Companies.
One thing to bare in mind is if your house Insurance is due go for a company that will do house and car insurance as you might get it cheaper.

Admiral 0800 600 800 http://www.admiral.com/
Adrian Flux 01553 777 240 http://www.adrianflux.co.uk/
AON 01384 552 670 http://www.aon.com
A-Plan 0845 071 123 http://www.aplan.co.uk/
AXA 0800 015 4292 http://www.axa-motor.co.uk
Bell Direct 0800 140 180 http://www.belldirect.co.uk/
Bennetts 0990 202090 http://www.bennetts.co.uk/
Bugdet Insurance 0800 028 9044 http://www.budgetinsurance.com/
Catterall 01254 695 055 http://www.chris-thompson.co.uk/
Churchill Car Insurance 0800 200 331 http://www.churchill.com
Cis 08457 464646 http://www.cis.co.uk/
CoverSure (RallySure) 01829 733 880 http://www.dmatters.co.uk/
Crowthorne Insurance 01344 771626 http://www.crowthorne.co.uk
Direct Line Insurance 0845 246 8701 http://uk.directline.com/
Elephant 0870 6080668 http://www.elephant.co.uk
Endsleigh 0800 028 3571 http://www.endsleigh.co.uk
Footman 0121 651 6250 http://www.footmanjames.co.uk
Graham Sykes 0870 444 6319 http://www.graham-sykes.co.uk/
Greenlight 01277 263 030 http://www.greenlight-insurance.co.uk/
HIC - 08451 290 290
Hill House Hamond 01733 310899 http://www.hhh.co.uk/
Keith Michaels 0181 642 7868 http://www.keithmichaels.co.uk
Liverpool Victoria 0800 514 514 http://www.liverpoolvictoria.co.uk
More Than Insurance 0800 072 4186 http://www.morethan.com
Motor Quote Direct 0800 48 44 33 http://www.motorquotedirect.co.uk/
Nash Warren 0121 561 4484 http://www.nashwarren.co.uk/
Norwich Union 0870 242 0800 http://www.norwichunion.com/
Peart 0870 240 2972 http://www.peart.co.uk/
Peoples Choice 0800 614 824 http://www.peopleschoice.co.uk/
Performance Direct 08704 203896 http://www.performancedirect.co.uk/
Privilege Insurance 0113 292 5555 http://www.privilege.com/
Quinn Direct 0845 850 0845 http://www.quinn-direct.com/
QuoteLine Direct 0870 444 0870 http://www.quoteline-direct.co.uk/
RAC 0845 3000 755 http://www.rac.co.uk
Sainsburys 0800 032 0000 http://www.sainsburysbank.co.uk/insurance/
Tesco Cheap Car Insurance 0845 300 9900 http://www.tesco.com
The AA 0870 606 0483 http://www.theaa.com
Hastings Direct 0800 00 1066 http://www.hastingsdirect.com
Esure 0845 603 7873 http://www.esure.com
Halifax 0845 608 9913 http://carinsurance.halifax-online.co.uk
Eagle Star 08459 45 45 67 http://www.eaglestar.co.uk
Lloyds TSB 0800 056 3040 http://www.insurance.co.uk
Screen Trade 0800 435 207 http://www.screentrade.co.uk
Its4me 0870 0131 464 http://www.its4me.co.uk/
The Insurance Centre 0709 2511050 http://www.theinsurancecentre.co.uk
Quote-A-Car 08707 709075 http://www.quotea.co.uk/quotea/default.asp